In order to do that, I suppose the program needs to check every character to analyze what language is used which is kinda a hassle.
Another option to reduce the issue is to let the user automatically join their language channel based on their location/IP address (easier to implement than your request). Of course this is only applied when they're new in this game (1~2 months).
They should know already that their language channel exists forthem to chat using the specific language instead of chatting in #osu and other channels.
If they chat in a language that doesn't match the required language, then the moderators can inform them using !faq command.