Win32COM & Detaching from automation servers

[Brian]

I've searched this newsgroup for an answer to my problem, but haven't
come up with anything.  (Perhaps the solution is obvious and I'm just
not seeing the forest for the trees...)

I want to write a Python program on Windows which will use the
automation interface for Excel.  What I want it to do is launch Excel,
open a template, stuff data into it (based on command line parameters
to the Python app), detach from Excel and exit, leaving Excel open.

I know how to do everything except for the detach part.  Any help is
much appreciated.