SSL Cert for site

[filch]

How can I set up a site to use an SSL cert on a different port like 444. Right now, every time I try to add a self signed cert to a site it complains that there already is a cert for the server IP. Do I have to add another IP in order to use a cert on one of my sites. It seems that once the cert is in use for ISPConfig itself, I can no longer use a self signed cert on any other sites.

Dave