I've never had to do it, but from perlre, it seems like it's just a matter of using the proper locale:

If the "utf8" pragma is not used but the "locale" pragma is, the classes correlate with the usual isalpha(3) interface (except for `word' and `blank').

and from perllocale :

Here is a code snippet to tell what "word" characters are in the cur- rent locale, in that locale's order:

   use locale;
   print +(sort grep /\w/, map { chr } 0..255), "\n";
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Compare this with the characters that you see and their order if you state explicitly that the locale should be ignored:

   no locale;
   print +(sort grep /\w/, map { chr } 0..255), "\n";
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