You would need to write a Visual Studio addin that writes to a log file that
Outlook would pick up and use for journaling. That's how other journaling
addins like the one that used to be available for AutoCAD (might still be)
do it.
I believe the format for the log file and specs for it are on MSDN, or at
least they used to be. I haven't looked at those specs in about 6 or 7
years, so I'm not sure they're still available. Maybe Google would be your
friend trying to hunt the specs down.