(defun c:foo (/ e elev ss)
  (if
    (and (setq elev (getdist "\nEnter elevation: ")) (setq ss (ssget ":L" '((0 . "MULTILEADER")))))
     (while (setq e (ssname ss 0))
       (entmod (mapcar '(lambda	(x)
			  (if (member (car x) '(10 12 110))
			    (list (car x) (cadr x) (caddr x) elev)
			    x
			  )
			)
		       (entget e '("*"))
	       )
       )
       (ssdel e ss)
     )
  )
  (princ)
)