Way to move selection to a specified height?

Sometimes modeling in plan view, I end up with elements slightly above or below the ground plane.
I am trying to find a way to then move these selected groups back to “0” on the Z axis.
The problem is, I have no way of knowing how far off “z0” the selection is and the move tool input box is relative, not absolute. That is: I can’t enter a Z coordinate of “0” and have it move to model space Z zero.
Currently, I shift to a front elevation view and then eyeball, with the move tool locked on the Z axis.
It would be great if the Object Info Dialog box (or somewhere else) could show coordinates of the selection so I would then be able to determine the precise offset needed to get the group back to model space z 0.
Any ideas would be appreciated.
Jeremy C.

The ‘Text’ too reveals the coordinates of endpoints when clicking on them in their conctext.
So does the ‘Tape Measure’ tool when hovering over them in any drawing context.

You can send a collection by grabbing it at your desired endpoint and move it up or down and then typing [, ,0] and hit [Enter]

Excellent - thank you. The tape measure does show the coordinates I was looking for - I probably would never have found this without your help. And, the [, ,0] works! I hadn’t tried the move up or down before entering.
Many thanks!