use Encode;

ex("c:\\fil\x{e9}.txt");
ex("c:\\fil" . chr(0xc3) . chr(0xa9) . ".txt");
ex("c:\\fil" . pack("U", 0xe9 ) .  ".txt");

sub ex {
	my $f2 = shift;

	my $f = $f2;
	print $f;
	print ((-e $f) ? " exists" : " doesn't exist");
	print "\n";

	my $f = Encode::decode( 'utf8', $f2);
	print $f;
	print ((-e $f) ? " exists" : " doesn't exist");
	print "\n\n";

}

##</code><code>##

c:\filé.txt exists
Wide character in print at C:\ex.pl line 16.
c:\fil�.txt doesn't exist

c:\filé.txt doesn't exist
c:\filé.txt doesn't exist

c:\filé.txt doesn't exist
Wide character in print at C:\ex.pl line 16.
c:\fil�.txt doesn't exist