Moved and merged the topic, wasn't correct sub-forum either.
It was previously explained with non-latin languages:
Theoretically you could do it to some extend, but you will have to edit existing font.bmp file and make a "hackjob" by redrawing existing characters and then editing strings accordingly (by still following with latin characters) or replace chars in the file afterwards.
I'm pretty sure that's how most "pirated" (or unofficial) russian game translators do it.