I have a similar problem and I don't get how you solved this.
I have a menu to start the game where you can pick the language. When playing you can go back to the menu, change the language and resume playing - no problem so far.
But I want the player to have the possibility to start a new game, when he was already playing - in the language he chooses then. (meaning : playing a game in language A, deciding to try it in language B fresh from the start)
So when I execute an autosave at the beginning of the game it saves the language picked first.
As far as I understood, this was the same problem you had @gabarts. How did you solve this?
Writing/Reading the config.ini won't help, because I want the player to pick the language, not save his first pick at a language. Using two autosaves won't do either, because the player will have only one autosave (in the language he picked first)
Edit: oh, with an extra splashscreen where you pick the language. Not really what I wanted. Does anybody have an idea for a different solution?