Use substr:

substr - get or alter a portion of a string 

SYNOPSIS:
=========
substr EXPR,OFFSET,LEN,REPLACEMENT 
substr EXPR,OFFSET,LEN 
substr EXPR,OFFSET 

DESCRIPTION:
============
Extracts a substring out of EXPR and returns it. 

There's a nice article about it at developer daily. If you want to learn more about handling fixed with data I recommend David Cross's book Data Munging with Perl

--
Brigitte    'I never met a chocolate I didnt like'    Jellinek
http://www.horus.com/~bjelli/         http://perlwelt.horus.at