ddclient getting internet IP from AP

[Jim]

FC 8
I'm using a  2WIRE783 router/modem AP from AT&T and I want  ddclient to 
be able to get the Internet IP for my network
so it can forward it to dyndns.com.
The other methods i'm using like "getip.com" and so on is not working, I 
think they are shutting me out.
Is there a HowTo someplace to explain howto get it from the AP.

Thanks
Jim