Airport extr port setting w/SL server

When moving our offices to a new location I lost all the settings on my Airport extreme.

I have a Mini Server with Snow Leopard Server 10.6.8 that's connected to the internet via an Airport Extreme base station.

We have a set of wikis that we usually acces from the internet with a domain name for which the IP was managed by Dyndns. I can access the wiki locally with the local adress (http://miniserver.local/groups/xxx/calendar/ or http://miniserver.local/groups/xxx/wiki/) but can't do it with the domain name as we used to before.

I've opened port 80 on the airport extreme but it still doesn't work.

Any ideas?