Without getting into a lot of details, version numbers, etc., the bottom line is that you need a very old Mac running a very old version of the Mac operating system to be able to configure the old AirPort Extreme.
Anything from Leopard, Snow Leopard, Lion or Mountain Lion cannot be used to configure the Extreme. I doubt that Tiger,which came before Leopard could be used.
Sorry to be blunt, but unless you can go back 7-8 years on a Mac, there is no chance that you will be able to configure the old AirPort Extreme that you have.
I see that John has posted some other suggestions. They are worth a try.....you never know. I would love to be wrong.