AutoCAD Visual LISP / AutoLISP :: Proper Structure For Using Cmdecho And Undo G Together?

I like to suppress command echos in my routines, and I also like to bracket them with (command "undo" "g") at the start and (command "undo" "e") at the end.But if they have this structure:

(defun C:XXX ()
  (command "undo" "g")
  (setvar "cmdecho" 0)
  (setvar "cmdecho" 1)
  (command "undo" "e")
  (princ))

The first command "undo" regurgitates junk on the command line that I don't like to see.On the other hand, if I do this:

(defun C:XXX ()
  (setvar "cmdecho" 0)
  (command "undo" "g")
  (command "undo" "e")
  (setvar "cmdecho" 1)
  (princ))

The command line stays clean, but if I Undo after the command, "cmdecho" stays set at 0.