Thanx, I did 'use utf8;', but binmode, fixed my problem. I am still struggling to understand unicode concepts. :(.
With binmode, it works using ether hex or eval, also, I've tried pack('U', hex $1), it works.
For some reason, I thought, pack 'U', takes hex digits as an argument, but actually I've had to convert it to decimal, because pack('U', $1) didn't work.