i tried the following code.but still problem
the input.txt contains 4 chinese characters in a line.

use utf8;
use Encode;
open INPUT,"<:utf8","D:\\try_unicode\\input.txt" or die "Couldn't open
+ file: $!";

close STDOUT;
open STDOUT ,">:utf8","D:\\try_unicode\\output.doc" or die "Couldn't o
+pen file: $!";

$unpacking=<INPUT>;
chomp($unpacking);
print "\nunpacking1   :" ,decode("utf8",unpack("x4A4",$unpacking)),"\n
+";
print "\nunpacking2   :" ,unpack("U4A4",$unpacking),"\n";

close INPUT;
close STDOUT;
[download]

i used U4 still its giving some sequence of numbers.
i trien to x4 to null byte the four chinese characters its not working .
i tried using A4 also its not working.