Attributing Objects that are inputed into Grasshopper

I've run into a number of cases where I've wanted to somehow attribute objects that are being sent to grasshopper. Say for instance I have 10 curves that I'm sending to grasshopper. Curves 1-3 are part of "group 1", curves 4-7 are part of "Group 2", and curves 8-10 are part of Group 3. Yet I want the number of curves, the number of groups, and the groups the curves are assign to to be something that can be changed easily by the user in Rhino with out changing the Grasshopper definition.

I was thinking I could use a C# component to extract the layer that each object resided on. Yet I can't seem to figure out how to find the layer of a RMA.OpenNURBS.OnGeometry type object.

I also looked at the Set/GetUserString methods, but there doesn't seem like an easy way for the user to edit or view these values with out me writing a separate plug in for Rhino.