You poor fella... As said above you really shouldn't be tasked with something like this, but stick around here and learn Perl.

I've had to document\comment some shifty code that someone else wrote and they were never heard from again so I was on my own... (Thanks Paco!!)

Anyway, what I did was print the code out using an editor that uses syntax colors.(The original code was on Linux and it needed to be changed to Windoze). I use editplus http://www.editplus.com/ tape all the pages together and bust out the crayons and start pointing which subs are going where in different colors etc.. Then document using a flow chart. If you see spots that aren't commented and you know what it's doing, add in proper comments.

Hang around here long enough, and before long you'll bump into that really cool script you first wrote, and say... Ahh what was I thinking... This could be better!

Good Luck!