Airport Extreme & Super Duper!
 

So,
I've got my external hard drive connected to my airport extreme, but Super Duper will not allow me to backup using this airport?
Any workarounds?

Please describe the solution in a very simple way - I'm not a mac expert...

Thanks in advance

Larsen

Sure. See "Backing up over a network" in the User's Guide, and the "Airport Disks" post at the blog.