You're probably going to have to deal with the different parts independantly. For example..

#!/usr/bin/perl -w

use strict;

my $trunc = 1;
my $tap = 'A';
my $tapoftap = 1;
my ($x, $y, $z);

for $x (1..20) {
    for $y (1..10) {
        for $z (1..10) {
                print "T$trunc$tap$tapoftap\n";
                $tapoftap++;
        }
        $tapoftap =1;
        $tap++;
    }
    $trunc++;
    $tap = 'A';
}
[download]

Just an example. I don't know how you really need to deal with them. As far as I know, I don't think you can create your own user defined types in perl.

Also, you could use the above to build an array or a list depending on what you're doing..

There's also the option of creating a sub that returns a value based on what you want to do. Something that takes the current Trunc-tap-subtap and a keyword that signifies which you want to increment.

Hope this helps..
Rich