block byblock transparency

[jim78b]

(defun c:setbyblock ( / _byblock e n x a sel c)

    (defun _byblock ( n l / a e x )
        (if (and (setq e (tblobjname "BLOCK" n)) (not (member n l)))
            (while (setq e (entnext e))
                (setq x (entget e))
                (if (setq a (assoc 420 x))
                    (setq x (vl-remove (assoc 420 x) x))
                )
                (if (setq a (assoc 62 x))
                    (entmod (subst '(62 . 0) a x))
                    (entmod (append x '((62 . 0))))
                )
                (if (= "INSERT" (cdr (assoc 0 x)))
                    (_byblock (cdr (assoc 2 x)) (cons n l))
                )
            )
        )
        nil
    )

    (prompt "\nSelect Blocks: ")
    (setq sel (ssget (list (cons 0 "INSERT"))))
    (setq c 0)
    (repeat (sslength sel)
        (setq n (ssname sel c))       
        (_byblock (cdr (assoc 2 (entget n))) nil)
        (setq c (1+ c))
    )
    
    (command "_.regen")
    (princ)
    
)

Merry Christmas and best wishes to all, I would kindly need you to change this code so that it also makes the byblock transparency in addition to the color of the blocks