use POSIX 'locale_h';
my $loc = 'de_DE.UTF-8';  # German locale, for example. Run 'locale -a'
#+ to get the exact locale name
setlocale(LC_CTYPE, $loc)
 my $suspect = "vähicule";
 if($suspect =~ /^\w+$/) {
  		print STDERR "MATCHES\n";
 }