An association list is nice for this and can easily be generated if A=1 B=2 etc.
(defun c:foo (/ a myblks)
(setq
myblks (mapcar
'(lambda (x) (list x (strcat "Block" (itoa (- (ascii (substr x (strlen x))) 64)))))
'("BlockA" "BlockB" "BlockC")
)
)
;; (("BlockA" "Block1") ("BlockB" "Block2") ("BlockC" "Block3"))
(foreach blk myblks
(if (and (tblsearch "BLOCK" blk) (set a (assoc blk myblks)))
(command "-insert" (cadr a) "0,0" "" "" "")
)
)
(princ)
)