Assuming you need compatibility with R14, this means that the use of Visual LISP is out.
So, using Vanilla AutoLISP,
You could cycle through the block definitions in the drawing using:
And see if there are any references to the block in question within the other block definitions.Code:(defun GetObj (bObj) (if (setq bObj (entnext bObj)) (cons bObj (GetObj bObj)))) (GetObj (tblobjname "BLOCK" "Block_Name"))
But, for all this trouble, surely the purge call just returns "No unreferenced blocks found." does it not?
Hope this helps,