SCCM, Task sequence, country, region

echo set working dir
set w=%temp%
if not exist "%w%\mount" md "%w%\mount"
dism /Mount-wim /WimFile:install.wim /index:1 /MountDir:"%w%\mount"
dism /image:"%w%\mount" /Set-Syslocale:lv-LV
dism /image:"%w%\mount" /Set-UserLocale:lv-LV
dism /image:"%w%\mount" /Set-TimeZone:"FLE Standard Time"
dism /image:"%w%\mount" /Get-Intl
dism /unmount-wim /mountdir:"%w%\mount" /commit
if exist "%w%\mount" rd "%w%\mount" /Q /S

dism /image:"%w%\mount" /Get-Intl just list the settings active.
You can see all available languages with command

tzutil /l

This will list content like:

(UTC-12:00) International Date Line West 
Dateline Standard Time

(UTC-11:00) Coordinated Universal Time-11 
UTC-11

(UTC-10:00) Hawaii 
Hawaiian Standard Time

(UTC-09:00) Alaska 
Alaskan Standard Time

(UTC-08:00) Baja California 
Pacific Standard Time (Mexico)

(UTC-08:00) Pacific Time (US & Canada) 
Pacific Standard Time

(UTC-07:00) Arizona 
US Mountain Standard Time

(UTC-07:00) Chihuahua, La Paz, Mazatlan 
Mountain Standard Time (Mexico)

(UTC-07:00) Mountain Time (US & Canada) 
Mountain Standard Time

(UTC-06:00) Central America 
Central America Standard Time

(UTC-06:00) Central Time (US & Canada) 
Central Standard Time

(UTC-06:00) Guadalajara, Mexico City, Monterrey 
Central Standard Time (Mexico)

(UTC-06:00) Saskatchewan 
Canada Central Standard Time

(UTC-05:00) Bogota, Lima, Quito, Rio Branco 
SA Pacific Standard Time

(UTC-05:00) Chetumal 
Eastern Standard Time (Mexico)

(UTC-05:00) Eastern Time (US & Canada) 
Eastern Standard Time

(UTC-05:00) Indiana (East) 
US Eastern Standard Time

(UTC-04:30) Caracas 
Venezuela Standard Time

(UTC-04:00) Asuncion 
Paraguay Standard Time

(UTC-04:00) Atlantic Time (Canada) 
Atlantic Standard Time

(UTC-04:00) Cuiaba 
Central Brazilian Standard Time

(UTC-04:00) Georgetown, La Paz, Manaus, San Juan 
SA Western Standard Time

(UTC-03:30) Newfoundland 
Newfoundland Standard Time

(UTC-03:00) Brasilia 
E. South America Standard Time

(UTC-03:00) Buenos Aires 
Argentina Standard Time

(UTC-03:00) Cayenne, Fortaleza 
SA Eastern Standard Time

(UTC-03:00) Greenland 
Greenland Standard Time

(UTC-03:00) Montevideo 
Montevideo Standard Time

(UTC-03:00) Salvador 
Bahia Standard Time

(UTC-03:00) Santiago 
Pacific SA Standard Time

(UTC-02:00) Coordinated Universal Time-02 
UTC-02

(UTC-01:00) Azores 
Azores Standard Time

(UTC-01:00) Cabo Verde Is. 
Cape Verde Standard Time

(UTC) Casablanca 
Morocco Standard Time

(UTC) Coordinated Universal Time 
UTC

(UTC) Dublin, Edinburgh, Lisbon, London 
GMT Standard Time

(UTC) Monrovia, Reykjavik 
Greenwich Standard Time

(UTC+01:00) Amsterdam, Berlin, Bern, Rome, Stockholm, Vienna 
W. Europe Standard Time

(UTC+01:00) Belgrade, Bratislava, Budapest, Ljubljana, Prague 
Central Europe Standard Time

(UTC+01:00) Brussels, Copenhagen, Madrid, Paris 
Romance Standard Time

(UTC+01:00) Sarajevo, Skopje, Warsaw, Zagreb 
Central European Standard Time

(UTC+01:00) West Central Africa 
W. Central Africa Standard Time

(UTC+01:00) Windhoek 
Namibia Standard Time

(UTC+02:00) Amman 
Jordan Standard Time

(UTC+02:00) Athens, Bucharest 
GTB Standard Time

(UTC+02:00) Beirut 
Middle East Standard Time

(UTC+02:00) Cairo 
Egypt Standard Time

(UTC+02:00) Damascus 
Syria Standard Time

(UTC+02:00) E. Europe 
E. Europe Standard Time

(UTC+02:00) Harare, Pretoria 
South Africa Standard Time

(UTC+02:00) Helsinki, Kyiv, Riga, Sofia, Tallinn, Vilnius 
FLE Standard Time

(UTC+02:00) Istanbul 
Turkey Standard Time

(UTC+02:00) Jerusalem 
Israel Standard Time

(UTC+02:00) Kaliningrad (RTZ 1) 
Kaliningrad Standard Time

(UTC+02:00) Tripoli 
Libya Standard Time

(UTC+03:00) Baghdad 
Arabic Standard Time

(UTC+03:00) Kuwait, Riyadh 
Arab Standard Time

(UTC+03:00) Minsk 
Belarus Standard Time

(UTC+03:00) Moscow, St. Petersburg, Volgograd (RTZ 2) 
Russian Standard Time

(UTC+03:00) Nairobi 
E. Africa Standard Time

(UTC+03:30) Tehran 
Iran Standard Time

(UTC+04:00) Abu Dhabi, Muscat 
Arabian Standard Time

(UTC+04:00) Baku 
Azerbaijan Standard Time

(UTC+04:00) Izhevsk, Samara (RTZ 3) 
Russia Time Zone 3

(UTC+04:00) Port Louis 
Mauritius Standard Time

(UTC+04:00) Tbilisi 
Georgian Standard Time

(UTC+04:00) Yerevan 
Caucasus Standard Time

(UTC+04:30) Kabul 
Afghanistan Standard Time

(UTC+05:00) Ashgabat, Tashkent 
West Asia Standard Time

(UTC+05:00) Ekaterinburg (RTZ 4) 
Ekaterinburg Standard Time

(UTC+05:00) Islamabad, Karachi 
Pakistan Standard Time

(UTC+05:30) Chennai, Kolkata, Mumbai, New Delhi 
India Standard Time

(UTC+05:30) Sri Jayawardenepura 
Sri Lanka Standard Time

(UTC+05:45) Kathmandu 
Nepal Standard Time

(UTC+06:00) Astana 
Central Asia Standard Time

(UTC+06:00) Dhaka 
Bangladesh Standard Time

(UTC+06:00) Novosibirsk (RTZ 5) 
N. Central Asia Standard Time

(UTC+06:30) Yangon (Rangoon) 
Myanmar Standard Time

(UTC+07:00) Bangkok, Hanoi, Jakarta 
SE Asia Standard Time

(UTC+07:00) Krasnoyarsk (RTZ 6) 
North Asia Standard Time

(UTC+08:00) Beijing, Chongqing, Hong Kong, Urumqi 
China Standard Time

(UTC+08:00) Irkutsk (RTZ 7) 
North Asia East Standard Time

(UTC+08:00) Kuala Lumpur, Singapore 
Singapore Standard Time

(UTC+08:00) Perth 
W. Australia Standard Time

(UTC+08:00) Taipei 
Taipei Standard Time

(UTC+08:00) Ulaanbaatar 
Ulaanbaatar Standard Time

(UTC+09:00) Osaka, Sapporo, Tokyo 
Tokyo Standard Time

(UTC+09:00) Seoul 
Korea Standard Time

(UTC+09:00) Yakutsk (RTZ 8) 
Yakutsk Standard Time

(UTC+09:30) Adelaide 
Cen. Australia Standard Time

(UTC+09:30) Darwin 
AUS Central Standard Time

(UTC+10:00) Brisbane 
E. Australia Standard Time

(UTC+10:00) Canberra, Melbourne, Sydney 
AUS Eastern Standard Time

(UTC+10:00) Guam, Port Moresby 
West Pacific Standard Time

(UTC+10:00) Hobart 
Tasmania Standard Time

(UTC+10:00) Magadan 
Magadan Standard Time

(UTC+10:00) Vladivostok, Magadan (RTZ 9) 
Vladivostok Standard Time

(UTC+11:00) Chokurdakh (RTZ 10) 
Russia Time Zone 10

(UTC+11:00) Solomon Is., New Caledonia 
Central Pacific Standard Time

(UTC+12:00) Anadyr, Petropavlovsk-Kamchatsky (RTZ 11) 
Russia Time Zone 11

(UTC+12:00) Auckland, Wellington 
New Zealand Standard Time

(UTC+12:00) Coordinated Universal Time+12 
UTC+12

(UTC+12:00) Fiji 
Fiji Standard Time

(UTC+13:00) Nuku'alofa 
Tonga Standard Time

(UTC+13:00) Samoa 
Samoa Standard Time

(UTC+14:00) Kiritimati Island 
Line Islands Standard Time

Source:
https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-7/dd744360(v=ws.10)

Language codes:
https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-7/dd744369(v=ws.10)