Comment by jeroenhd
As far as I can tell, the drive will still be accessible, it'll just require the character equivalent to € on the other code page as a drive letter.
As long as your code page doesn't have gaps, that should be doable. It'll definitely confuse the hell out of anyone who doesn't know about this setup, though!
I don't think it works that way, the actual drive letter is a UTF-16 Unicode path. The application must be able to provide an "ANSI" string that encodes to that UTF-16 value if it uses an "ANSI" function to open the file. It's not like 8-bit systems where they just want the same 8-bit value.