Tag or Text note based on a selection of elements

Is it possible to use a tag (or plain text note) that automatically fills out based on the number of elements selected?

Basically I do a lot of schools and I have runs of lockers that would be great to have a Dynamo graph that would work similarly to the parking space renumber scripts that have been around a while. I would like to draw a spline through a row of lockers or a window selection, either method would be fine, and have dynamo let me pick a placement location for the tag/text note with the number of lockers in my selection.

Is this even a doable thing in Dynamo?

See image. Blue markup represents the selection of elements

Thanks in advance

Yes it seems doable. you can post your rough graph.