Kei-Koo
You still have to tell us, how you'll define that grid (graphical element vs. known coordinates), from this perspective Stefans request for an example might be really helpfull.
On the other hand it doesn't matter how to retrieve the coordinates (via export or via VBA scan). The question is, what should happen with the results ? You might create an Excel sheet and embed this in your drawing or go the hard way and create the elements (text and lines) for an 'internal' table. This will influence the possibilities you have for your automation task.
I see no use for tags here, as this will definitively be a very manual process without any guarantee that those informations are correct or even stored at all (the most critical problem with tags), if someone (by mistake or willingly) kills the tag, your absolutely left alone.
Michael