Hi There,
The OS Snapshot wizard is a component of Repackager, so you'll want to follow the same steps in the help document "Installing the Remote Repackager on a Clean Machine".
Once you've done that, just browse to the drive where you've mapped Repackager to, and run 'OSSnapshot.exe'.
Your idea of automating everything sounds pretty good, but I don't think there exists commandline switches available for OSSnapshot.exe to do so.
Hope this gets you started!
--Cary