You can do the opposite and control autocad/Bricscad from Excel may be an easier way.
A good method suggested by others, uses one dwg the way was to import the dwg block into current dwg, explode etc, run the size changes etc then wblock as that lets you save with a new name. May sound silly but erase all, import block, set sizes , wblock. As its all happening in current dwg no need for a script.
I would have to check wether "saveas" will work also as that allows more scope like layouts with title block etc. Un tested !!