domtool config

Next you need "port forwarding" of http requests for your domain to your own httpd (so that you don't need to use addresses like http://www.siebengang.net:8880/index.html, but http://www.siebengang.net/index.html gets "mapped" to port 8880). In the domtool setup for http://www.siebengang.net/ this looks like

domain "siebengang.net" with
  (* NS/DNS/Mail stuff omitted *)
  web "www" with
    proxyPass "/" "http://bog:8880/";
    proxyPassReverse "/" "http://bog:8880/";
  end;
end;

That should be about all you need...