Yes, I have an so far no go.

I am currently testing the following within the called CMD's, and on first pass, it looks like this may be closer to what I want.

 Code:
@echo off
cls
Set TempWS=%LocalAppData%\TempWS.vbs
:: Create a temporary WSHscript
Echo Set wshShell = CreateObject( "WScript.Shell" ) > %TempWS%
Echo wshShell.Popup "Software is being upgraded on your workstation." ^& vbCrLf ^& _ >> %TempWS%
Echo 				"Please leave your machine alone." ^& vbCrLf ^& _ >> %TempWS%
Echo				"Your computer will be rebooted once this is complete.", 60, _ >> %TempWS%
Echo				"IT Admins are upgrading your machine", 64 >> %TempWS%
Wscript.exe %TempWS%
Del %TempWS%
exit


Refrenced code originally from this lovely site - http://www.robvanderwoude.com/usermessages.php

Will be putting this through end to end test shortly.

Lan