How can I change the Region to Germany with Language English (US) on Android 6?

[AC Question]

I've got the Huawai P9 Plus with Android 6. When I set the Language to "English (US)", the list of Regions I can select from is very limited. For example, I don't find Germany. Is there any trick to set the Region to whatever I want while the Language is set to "English (US)"?