#!/usr/bin/perl

use warnings;
use strict;
use locale;
use POSIX qw(locale_h);

my $locale = "ru_RU.CP-1251"; #Russian Windows locale (as i think)
my $new_locale = setlocale(LC_ALL, $locale);
die "Could't set locale" if ($new_locale ne $locale);

print uc("some_string_in_russian"), "\n";