I've been using Zoneedit for free for 10 years now. They do have a support forum which will be of more help to you:
http://forum.zoneedit.com/index.php.
Your question is confusing, at least to me. I'm not sure you understand how DNS works. If you want to use Zoneedit for your DNS then you will need to set your name servers on your Godaddy account to the Zoneedit name servers. You don't really point your server anywhere rather you server just listens and Zoneedit will direct all traffic to the static IP of your server based on your host name. You purchased the host name at Godaddy but you are telling Zoneedit to hold the records that will pointthat host name to your IP.