(defun c:rebatimento()
  (setq obj (ssget))
  (command "._COPYclip" obj (getpoint "\nEnter base point: ") "")
  (setq coord (getpoint "\nEnter the coordinates to paste the object: "))

; Get elevation of reference surface and point
  (setq zref (getreal "\nEnter value of reference surface:"))
  (setq zpont (getreal "\nEnter the value of the point: "))

; Substitute the y coordinate
  (setq finalcoord (list (nth 0 coord) (* (- zpont zref) 5) 0.0))

; Repeat the paste process until the user cancels
  (while
    (progn
      (command "._pasteclip" finalcoord "")
      (setq coord (getpoint "\nEnter the coordinates to paste the next object (or press Enter to cancel): "))
      (setq zpont (getreal "\nEnter the value of the point: "))
      (setq finalcoord (list (nth 0 coord) (* (- zpont zref) 5) 0))
    );progn
   );while

);defun