Is there a registry key I can enumerate to list the number of outstanding updates for all machines in a domain?

I'm scripting some Windows Update checks (the SUS console is reporting inaccurate data for a number of clients). I can interrogate the following key to grab the last time a client checked for, downloaded and installed updates:

HKLM\Software\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update\Results

(Detect, Download and Install return the values I need)

However, I can't seem to find anything in the registry that shows the number of updates currently outstanding. Is there a key that shows this?