Ability to populate a group with a dynamic query based on IP address ranges and subnets

I would like to build a group and have it populated with systems that meet a specific IP address range or specified subnet.

Example:

Baltimore nodes group = (Dynamic Query) All nodes on 172.30.33.0/22 subnet

OR

All nodes starting with 172.30.33.1  thru 172.30.33.250

Surely this can't be too hard to implement and would be useful for many needing to group systems by IP.