Change gmod ip?

How would I change my ip address from my current one, to my dyndns one? I know there technically the same ip, but being as im on a dynamic ip and not a fixed one, I would like to use it so people who favorite my server will favorite the dyndns.org ip instead of my actual ip.

Any ideas?

It would suggest to set it in your router settings: https://www.dropbox.com/s/l009jueczda1y3t/Screen%20Shot%202012-11-22%20at%2023.11.29.png

I would if I could but I cant. Virgin media “super” hub does not support it for some batshit reason.