Thanks, but I was already aware of all this (I was the guy with the null username).
I think command=2 is explorer.exe and command=3 is IE.
I could start experimenting trying to find what commands there are, but there has to be a better way to find out. I'm going to keep searching microsoft.com.
I found the CLSID in the registry for .scf files:
{57651662-CE3E-11D0-8D77-00C04FC99D61}