G'day moesplace,

Welcome to the monastery.

The basic tools you need for this are the readdir & reverse functions and the .. operator used as a flip-flop. Here's some skeleton code to show the technique:

#!/usr/bin/env perl -l

use strict;
use warnings;

my $base_dir = './pm_proc_dir_dates_rev_dir';
my $start_date = '20110228';
my $end_date = '20110302';

opendir my $dh, $base_dir or die "Can't open '$base_dir': $!";

for (reverse grep { /^[^.]/ } readdir $dh) {
    if (/$end_date$/ .. /$start_date$/) {
        print "+ Processing: $base_dir/$_";
    }
    else {
        print "- Skipping: $base_dir/$_";
    }
} 

closedir $dh;
[download]

Output:

$ pm_proc_dir_dates_rev.pl
- Skipping: ./pm_proc_dir_dates_rev_dir/20110303
+ Processing: ./pm_proc_dir_dates_rev_dir/20110302
+ Processing: ./pm_proc_dir_dates_rev_dir/20110301
+ Processing: ./pm_proc_dir_dates_rev_dir/20110228
- Skipping: ./pm_proc_dir_dates_rev_dir/20110227
[download]

Here's a listing of the ./pm_proc_dir_dates_rev_dir directory:

$ ls -1a ./pm_proc_dir_dates_rev_dir
.
..
20110227
20110228
20110301
20110302
20110303
[download]