According my test result, Win32::MsgBox() can not support Unicode string. The following is the code:

my $teststr = "\x{6211}\n"; #This is a Chinese Character
MsgBox("$teststr\n");

use Win32;
sub MsgBox {
	my ($msg, $flag, $title) = @_;
	Win32::MsgBox($msg,$flag,$title);
}

Finally it shows a string with messy code. Is there any other method I can use to pop out a message box with Unicode string as input? Thank you very much