Why? For example to not have diacritics in month names? Take them as examples as you can easily add them to a shell script to make in work the way you want.
I'm multi-lingual but try to separate business stuff for example (multi-lingual) from private stuff (mostly one language), so clashes between languages rarely happen.
But if it gets complicated I'll usually resort to Perl scripts to take care of pesky details. Sorting an associative array where the key is a string in unified form and the value is the multi-lingual target is rather easy in a script language which one is fluent in.