I dont think it gets anymore clear than this:
My ISP blocked port 80. How can I run a web server?
Don't worry, you can still run one!
Sign up and get started with ZoneEdit.
Make your web server listen on port number like "6000" or "5000"
Check to see if your web server works in a browser by using a URL:
http://3.4.5.6:6000/. Use the port number that you're listening on and the real IP address of your machine.
Add the "IP Address" for your web server in ZoneEdit: "ww2.domainname.com" points to "ip address".
Add a Web Forward entry for your domain called "www.domainname.com" that points to
http://ww2.domainname:6000/
We recommend turning cloaking off in this case, letting people know thay are going to
http://ww2.domainname.com:6000 is usually OK, and it allows the browser to perform better.