Sorry for wasting everyone's time, I managed to sort it.

If anyone else is a dumb as me, here's the solution.

#!/usr/bin/perl

use CGI qw/:standard/;
use strict;
use warnings;

$user='user1';

$cookie1 = cookie(-name=>'user',
          -value=>"$user",
          -expires=>'+1h');
          -path => '/', 
     print header(-cookie=>$cookie1);
[download]

Back to the books Thanks again!