Firstly; allow me to apologize for my seeming incoherent replies. But as I noted in the OP, the script(s) I'm currently using to help automate the process, must be responded to, anywhere from 60 - 90 seconds. So it makes it extremely difficult carry out a thought process, let alone, type them in a box. It plays hell, when trying to coordinate a group of routines for a Perl script. Hence my plea for help.

While I'm extremely grateful for the solution @anonymous, I must admit I'm also a bit disappointed. As I had hoped to solve it with your earlier hints. But not that disappointed! :)

Thanks!

Here's what I've used

#!/usr/bin/perl -w
use Modern::Perl;

use Net::CIDR qw/ cidr2octets /;

while(<STDIN>){
    s{\s+$}{};
    print "$_\n" for cidr2octets($_);
}
__END__
[download]

Which allows me to

$ unpack-cidr.pl < packed-cidr > unpacked-cidr
[download]

Once again, I'm really grateful for your taking the time to respond with the illusive logic I was seeking. This is all part of a much larger process, and this missing piece of the puzzle was just what I needed to put it all together. I'll post it all here, when I've completed it. As I suspect others will also gain from it.

Thanks again!