I got this to work:
(defun ax:Toggle-off (mGroup tBarName / tbar)
(setq tbar (vla-item (vla-get-toolbars (vla-item (vla-get-menugroups (vlax-get-acad-object)) mGroup)) tBarName))
(if (= (vla-get-visible tbar) :vlax-true) (vla-put-visible tbar :vlax-false))
(princ))
(defun ax:Toggle-on (mGroup tBarName / tbar)
(setq tbar (vla-item (vla-get-toolbars (vla-item (vla-get-menugroups (vlax-get-acad-object)) mGroup)) tBarName))
(if (= (vla-get-visible tbar) :vlax-false) (vla-put-visible tbar :vlax-true))
(princ))
;;;
(defun C:RARCH ()
(princ "\n*** ---- Resetting ARCH Menu Pulldown ---- ***")
(ARCH:GDFstandard)
(cond
((or (= (nth 0 (ARCH:Split (getvar "dwgprefix") "\\")) "Z:")(= (substr (getvar 'dwgname) 1 (- (strlen (getvar 'dwgname)) 5)) "Drawing"))
(progn (ax:Toggle-off "ARCH" "Arch2Program©")(ARCH:NotInDirectory)))
((or (/= (nth 0 (ARCH:Split (getvar "dwgprefix") "\\")) "Z:")(/= (substr (getvar 'dwgname) 1 (- (strlen (getvar 'dwgname)) 5)) "Drawing"))
(progn (ax:Toggle-on "ARCH" "Arch2Program©")(ARCH:InDirectory))))
(princ))
;;;
(defun rarchit (calling-reactor commandinfo) (C:RARCH) (princ))
(vlr-docmanager-reactor () '((:vlr-documentBecameCurrent . rarchit)))