Disregard. I think that datum gets cemented in stone once you go into the milling side for the first time but I finally realized I could just move the entire drawing around the datum to place it where I wanted.
I occassionally get frustrated trying to figure out how to do things in Dolphin (mainly because this is really the only CAD app I have ever used). Just when I think I have found something it can't do I stumble across how to do it. This software has been worth every penny I paid for it.