Have you tried scripts?
HERE is a thread that discusses them,
and
ANOTHER ONE.
and yet even
ANOTHER.
Also you could try ScriptPro, it comes with AutoCAD I believe. Just type SCRIPTPRO at the command line. Look at the help.
A script to open a drawing, zoom to extents, save the drawing, and close it would look like this:
open C:/directory/drawing1.dwg zoom e qsave close
open C:/directory/drawing2.dwg zoom e qsave close
open C:/directory/drawing3.dwg zoom e qsave close
open C:/directory/drawing4.dwg zoom e qsave close
Hope this helps.