Create Boundary in lisp from items on layer included nested blocks

I am trying to create a boundary using lisp, but if the items are in a block it wont work. So I am trying to figure out how to do it using the extend ssget functions.

here is the one that works when the items are not in a block:

(Command "-boundary" "a" "b" "n" (ssget "_X" '((8 . "*GRID*"))) "" "" pt "")

Here are the extended ssget items I just can't get them combined.

   ; (ssget "_:S") - selecting a single object
   ; (ssget "_:E") - selecting all objects crossing the selection box (can be also combined to e.g. (ssget "_:E:S")
   ; (ssget "_:N") - selecting objects including nested/child objects - e.g. with block references
   ; (ssget "_:D") - duplicate objects counted separately (2x selected object = 2 selections)
   ; (ssget "_:L") - stops users from selecting objects on locked layers
   ; (ssget "_:P") - rejects selection of viewports
   ; (ssget "_+.") - allows window selection even in the single selection mode - e.g. (ssget "_+.:E:S") (may not work in some localized versions of AutoCAD) 

Try to use NENTSEL function instead of SSGET.

Regards,

Try to use NENTSEL function instead of SSGET.

 

Regards,

I hate to ask, but I am not sure how to do that. I should clarify that I am trying to get items that are also not in a block just all items that are on a layer that contains the word "grid"