Even if you get past that issue, I don't think you'll be able to store those double-byte index values inside your database without switching it to UTF-16. That's something I run into constantly during migrations. Non-ASCII characters get converted to double-byte strings, meaning they won't fit inside the columns defined in databases with 8-bit codepages.
The icing on the cake is that I have no idea how this would affect searching. (Can a Windows client or web browser properly convey double-byte characters and make it all the way through CMOD down to the database for a query?)
Hopefully some of our users from Europe will be able to help with this.
-JD.