MyDLP - changing the https listening port of the web front end gui

I have run into a problem when I am creating a virtual ip to access MyDLP from the internet. The setup is that I have MyDLP installed and has an internal ip of lets say on port 443. I only have one public ip so the way I normally do this is to create a virtual ip with the public ip to the private ip and I configure port mapping so on the outside looks like myinternetip:4435 (I simply map internal port 443 to external 4435).

This is not working with MyDLP because every time you select a link in MyDLP it changes the full url so I can not get to the page (seems like pretty bad web coding to me if the application is changing the fqdn everytime).

Anyway, I am guessing the best way to resolve this is to change the port that the MyDLP server is listening on? Anybody have any ideas how to do this?

I found that if you edit the /etc/apache2/ports.conf and the /etc/apache2/sites-enabled/mydlp.conf files and follow this guide below then you can change the default ports and get MyDLP running on a non standard port. Pretty straight forward so I wanted to respond to my own question incase anybody else runs into this. I am no longer getting the errors with the fqdn that I was before with port forwarding.