How about pasting some code? Would be very helpful for finding the problem.

Nevertheless my script to do that would look like that:

use strict;
use warnings;
use LWP::Simple;

my $baseurl = "http://www.retrosheet.org/";

for (my $i = 0; $i < 100; $i++) {
    mirror("${baseurl}zipfile${i}.zip", "zipfile${i}.zip");
}
[download]

The code assumes that the zipfiles are at the servers root directory and called zipfile${number}.zip where the $number is between 0 and 99. You will need to adapt it to your specifications. Also you should add some error handling.

Cheers, Flo