Subtracting from z axis to get new point

So I want to insert a block that is below the initial insertion point without changing the block. I've been busting my brain trying to get this lisp routine to work correctly. I think I'm close I get a malformed error on input. Can anybody help me out?

(defun C:*789 (/ oldlayer pt1 pt2)

(setq pt1 (getpoint "\nChoose a point : "))

(setq x (/ (car pt1)

(setq y (/ (cadr pt1)

(setq z (/ (caddr pt1) - 0.353))

(setq pt2 (x y z))

(command

"insert" "C:/CAD_BLOCKS/J-Hangers/J-HANGER-050.dwg" pt2 ""

""

)

(PROMPT " \ Rotation Point")

(princ)

)

)

Welcome to CADTutor

Here are some quick corrections to your code:

(defun C:789 ( / pt1 pt2 x y z )
   (setq pt1 (getpoint "\nChoose a point : "))
   (setq x (car pt1))
   (setq y (cadr pt1))
   (setq z (- (caddr pt1) 0.353))
   (setq pt2 (list x y z))
   (command "_.-insert" "C:/CAD_BLOCKS/J-Hangers/J-HANGER-050.dwg" "_non" pt2 "" "" "\\")
   (princ)
)

For an explanation of the error, please refer to my Error Message Troubleshooter.

PS: Please edit your post and enclose your code with code tags:

[highlight][noparse]

[/noparse][/highlight] Your code here [highlight][noparse]

[/noparse][/highlight]

Much appreciated, I understand what I was doing wrong now!

You're welcome!