HELP: How to redefine a block (within a drawing) using macro script

This is the setup

DRAWING 1 (saved in c:\template)

contains Block A, Block B, Block C & Block D

DRAWING 2 (saved in d:\)

contains Block A, Block B & Block C

(I HAVE ADDED c:\template to the "support file search path")

How to draft the macro script such that only Block A & Block C from DRAWING 2 can be redefined base on Block A & Block C from DRAWING 1?

Thanks

i use the following script:

(load "f:/cad/Lisp-Scrips/blkredef.lsp")
;
(BlkRedef "f:\\cad\\Blocks\\---.dwg")
ATTSYNC
N
---

--- = blockname

(attsync part only for blocks with attributtes)

first load the lisp (blkredef.lsp)

PmxCAD

blkredef.lsp