Changing Windows locales on a per-process basis
Here is a a bit of a hack that might do it. I believe these settings are configured on a per users basis so I'm guessing you could:
- create a new user
- log in as that user
- setup the required settings for the app
- log out and back in as your normal user
- run the program as the newly created user (you can do this by holding shift then right clicking the exe and chosing "run as")
There's an open-source alternative to Microsoft AppLocale that is claimed to work up to windows 10, available on GitHub:
https://github.com/xupefei/Locale-Emulator
Its allows per-app locale settings, accessible via a context menu option.