In this case, I would recommend using a csv file import. Your text file would look like this:
Import this text file and your IP Addresses are all in that 172.16.0.0/16 subnet.
Awesome! Thank you sir. I had a feeling the feature was already there, and I just wasnt thinking out clearly.
Another easier way to do this is to use the Subnet Allocation Wizard. It automatically sets up the SuperNet and then you can set the size of your subnets and select them.