depends on
(1)how you are loading the .NET add-in
(2)if batch is kicked off before autocad starts or after and .net add-in is already loaded,thus it cannot be unloaded.
(1)
If using Startup Wizard (appload) then i'm not sure.
If using demand loading via registry, then toggle loadctrls from to some value other than load at startup (bitflag 2).
Search ARX Help for 'Creating AutoCAD Subkeys and Values'
(2)You could add a sub to your add-in that can be called by other programs to un-hook the acad/drawing.
Ronnie Wilkins, Jr.