[10.6 Server]Change default subnet InternetSharing

Greetings

I would like to change the default subnet for Internet Connection Sharing on Snow Leopard Server. The assistant that helps you setup this InternetSharing chooses 192.168.1.x and then works perfectly. But in our case we would like to have the subnet on 192.168.0.x
If found an easy solution for Snow Leopard ‘client’ on this site (http://www.macosxhints.com/article.php?story=20090510120814850), but it turned out not to comply with Snow Leopard Server.

Can anybody help me? Thanks in advance…