Well, controls and such aren't that bad. A new char matrix format is also needed (no biggie, working on it). The problem is saving to text, since each language has its own conventions for mapping 2-byte unicode to 1-byte ansi.
I'm thinking of adding a file like "Language.tbl" for each language, with rows of the form:
<ansi index (0..255)>:<unicode 2-byte char>
SubRip would revert to just truncating the second byte if the file for the current language is not present.