Ok. I found this from another site's forum....
"You would need 2 VBA apps:
1. From AutoCAD open and update Excel or a direct update of a csv file.
2. From Excel open and update Autocad or use Open Design software.
If it is just block refs this should be fairly easy if the block name is unique or you save the object handle in excel. WARNING: If a drawing has to be recovered the handle could change or the block name could change!!
This is why my blocks have a Record Number Attribute that is unique for each block insertion."
Sound correct? But I'm not that good at code(VBA).