$re1='(gain)';
     $re2='(:)';
     $re3='(Overall)';
     $re4='(:)';
     $re5='(\\d+)';
     $re6='(:)';
     $re7='(\\d+)';
     $re=$re1.$re2.$re3.$re4.$re5.$re6.$re7;
     if ($lookup =~ m/$re/isg) {

##</code><code>##

  $re = '(gain)(:)(Overall)(:)(\\d+)(:)(\\d+)';
  ...
  "$name $7\n"

##</code><code>##

    $reg1='(ERROR)';
    
    ...

     elsif ($lookup =~ m/$reg1/isg) 

##</code><code>##

#! perl -slw
use strict;
use LWP::Simple;

sub lookup {
    my( $hf, $name ) = @_;
    my $lookup = get(
        "http://rscript.org/lookup.php?type=track&time=62899200&user=$name&skill=all"
    );

    print "Looking up $name...\n";

    if( $lookup =~ m/gain:Overall:\d+:(\d+)/isg ) {
        print { $fh } "$name $7\n";
    }
    elsif( $lookup =~ m/(ERROR)/isg ) {
        print { $fh } "$name doesn't exist \n"
    }
    else{
        print { $fh } "$name 0\n";
    }
}

my $names = 'zezima';

open( LOOKUP, '>>rstlookup.txt' ) or die $!;

while( my( $name ) = $names =~ m/([a-z0-9_]+)/isg ) {
    lookup( \*LOOKUP, $name );
}
close( LOOKUP );