Use code like this (in a vbscript) to kick of the HTA
Const TemporaryFolder = 2
Set sTemporaryFolder = oFSO.GetSpecialFolder(TemporaryFolder)
sFile = oUtility.ScriptDir & "\Z-FinalConfig.hta"
oFSO.GetFile(sFile).Copy sTemporaryFolder & "\" & oFSO.GetFileName(sFile),True
'Create the cmd to start the HTA
sCmd="mshta.exe """ & sTemporaryFolder & "\Z-FinalConfig.hta"" "
'start the HTA, but don't wait for it to complete - otherwise we will never end the TS.
oShell.CurrentDirectory = sTemporaryFolder
sReturn=oShell.run (sCmd,1,False)
If you want a full example (also works in MDT 2010)
Final Configuration for Lite Touch, MDT 2008
http://www.deployvista.com/Default.aspx?tabid=78&EntryID=61