Handling unicode directory and filenames in Perl on Windows

I have an encoding problem with Perl and Windows. On a Windows 7 running Perl (strawberry 5.16) and a simple TK GUI I need to open files and/or access directories with non-english characters in their name/path. For opening files I've come out with this solution which seems to work fine:

#!/usr/bin/perl -w

use strict;
use warnings;
use Win32::Unicode::File;
use Encode;
use Tk;

my $mw = Tk::MainWindow->new;
my $tissue_but = $mw->Button(
    -text => 'Open file',
    -command =>  [ \&select_unicode_file ],
);
$tissue_but->grid( -row => 3, -column => 1 );
Tk::MainLoop();

sub select_unicode_file{
my $types = [ ['Txt', '.txt'],
          ['All Files',   '*'],];
my $input_file= $mw->getOpenFile(-filetypes => $types);
my $fh = Win32::Unicode::File->new;
if ($fh->open('<', $input_file)){
  while (my $line = $fh->readline()){
    print "\n$line\n";
  }
   close $fh;
}
 else{
  print "Couldn't open file: $!\n";
}
}

This correctly opens files such as Поиск/Поиск.txt

What I CANNOT do is to simply get a directory path and than process it. I think I should use use Win32::Unicode::Dir but I really can't understand the documentation.

It should be something like this:

#!/usr/bin/perl -w

use strict;
use warnings;
use Win32::Unicode::Dir;
use Encode;
use Tk;

my $mw = Tk::MainWindow->new;
my $tissue_but = $mw->Button(
    -text => 'Open file',
    -command =>  [ \&select_unicode_directory ],
);
$tissue_but->grid( -row => 3, -column => 1 );
Tk::MainLoop();

sub select_unicode_directory{
my $dir = $mw->chooseDirectory( );
my $wdir = Win32::Unicode::Dir->new;
my $dir = $wdir->open($dir) || die $wdir->error;
my $dir_complete = "$dir/a.txt";
open (MYFILE, $dir_complete );
    while (<MYFILE>) {
    chomp;
    print "$_\n";
}
close (MYFILE); 
}