Configuring an AEBS in OS 9.x
If you want to configure an Airport Extreme Base Station, according to Apple you need 10.1.5 or later, which is not much use if you are running OS 9.x
Jon Sevy makes a program that runs under OS 9 and can be used to configure an AEBS.
Sevy's site is here: http://gicl.cs.drexel.edu/people/sevy/airport/
You will need Java in order to run the utility. .