configure an airport extreme exactly like other wireless router

Thank you for your time. This is driving me crazy.

What I am trying to accomplish is to set up my airport extreme exactly like a current wireless router that is starting to go bad.

Here's the problem. This is for my place of work and the previous tech is not available, and he password protected the modem and router.

so i cannot get into the settings on either the old router or modem. also, there are two commercial photo printers hooked up to the current router via ethernet cable and they are set up with static IP's. the noritsu photo tech has told me that they must stay static ip, they're not able to do dynamic ip.

i've tried to set up the airport extreme with static settings, but i'm not familiar with doing this and so the hard wired printer computers will not connect to the internet.

and i can't have the network down for very long at all because people start throwing fits about the computer printers not working.

i can get into the computer printers and look at their static ip settings, but i don't know how to utilize those with the airport extreme.

i may just be missing something, there's probably an easy way to set it up or some check box i'm not checking.

and i can't reset the current modem or router and risk taking our lab down, that would cause all kinds of problems.

sorry for the rambling, any help would be greatly appreciated. and if you need any network numbers (ip, subnet, gateway) i can find those

on the printer computers. btw, the printer computers are running windows xp

thanks again!