Macro for measureing selected reference from assembly origin?

I'm wondering if anyone knows if a macro for this exists. I'm working with two very large imported assemblies, and in lieu of not being able to just overlay them to see where the differences are, I'd like to have a macro so that I can click on a point, edge, or cylindrical surface of anything in the assembly, and run a macro that launches the measure tool, and selects the assembly origin. I know this is a painfully simple thing, but I'm potentially going to be doing this a couple thousand times, and if I can save half of the clicks, that would be great.