I've been working on this for a while. I think now it's good enough to post it here.
Functions to do most everything with the DACL and ownership on all types of objects: Files or folders, Registry keys, services, Kernel and WMI objects, etc.
Here's a good example to test:
Local $TI = TimerInit()
Local $ret = _DenyAllAccess(@ScriptDir&'test.txt',$SE_FILE_OBJECT,@UserName)