I did the warning at the menu level.
Adding the following to the Arch Menu file:
[$(eval,Current Directory is ''$(getvar,dwgprefix)'')]
[$(eval,Warning ''$(getvar,users5)'')]
[Activate Directory ''Alert Message''](ARCH:NOZ);
(defun ARCH:NOZ ()
(setvar "users5" "Get Out of Z:\\ Directory")
(if (= (nth 0 (ARCH:Split (getvar "dwgprefix") "\\")) "Z:")
(ARCH:MsgBox2
" Arch Program : Info"
48
"
Arch Program© Alert
---------------------------------------------------------------------------
You are in the \"Z:\" Directory! GET OUT!!!"
4)
)
(princ))
(ARCH:NOZ)