That's one solution albeit you shouldn't have to jump through hoops like that.
Is it really that hard to implement an option to change the language through the in-game settings?
Anyway - if you're not opposed to do some ini-trickery:
On Windows look for a file called Engine.ini under:
for English. Save it and voila.
You can look up the parameters for the other available languages on the net.
Thank you Tupine! worked like a charm.