I'm looking to replace the selection option to it automatically selecting "BlockA".  How would you change this, please.
Code:
(setq ss (nth 3  (vlax-invoke    (vlax-ename->vla-object (car (entsel "\nSelect Block: ")))    'GetAttributes)))

One way:
 
Instead of
(car (entsel "\nSelect Block: "))
use
 
(ssname (ssget "_X" '((0 . "INSERT")(2 . "BlockA"))) 0)

Carl - does it replace the code above?  If not, I wonder how I would put that information in there so that it reads the block name, instead of asking for it.  Thanks!

This is the complete code after substitution:
 
(setq ss (nth 3  (vlax-invoke    (vlax-ename->vla-object        (ssname (ssget "_X" '((0 . "INSERT")(2 . "BlockA"))) 0))    'GetAttributes)))

Excellent.  Thanks, CarlB!