Assuming you have followed the instructions provided by No-IP, and have configured your dynamic DNS through No-IP properly, then you probably don't need to do anything more than configure whatever web server software you are using to be up and running and available to view off your local machine.  If you can bring it up locally, and you've configured your dynamic IP, then have someone test it; it's possible you won't need to do anything more.

You may want to experiment with the alias or aliases you use in your portal settings, however, as long as the remote viewer gets to the web site, even if the alias doesn't match DNN will just default to the home page (unless you're using DNN 2 or earlier).