It looks like you're trying to scan columns 4 though the end of the line for a particular pattern for each line.

Perhaps this sorta golf-like snippet will help.

#!/usr/bin/perl

use strict;
use warnings;

my $pattern = qr/[45fg]/; # Look for "4,5,f,g"

while(<DATA>) {
    chomp, 
    print "$_\n" 
        for grep { /$pattern/ }
            ((split /\t/)[3 .. s/\t(?!\n)/\t/g ]);
}

__DATA__
1   2   3   4   5   6   7   8   9   108 9   
a   b   c   d   e   f   g   h   i   j
[download]

Pax vobiscum,
-v.