I know some non-English decks have been made by basically redefining unused characters in the font to be characters with accents and such - e.g. you might not need a @ or # or $ in your text, so these can be repurposed to characters with accents. And if you're writing outside Decker you can just do a find and replace to convert it before pasting in. Very much depends on how many accented characters you need for that language though. And doesn't work well for input but if you're just looking to display text then it'll work.