Interestingly, I tried both methods (WMI query and SystemMonitor) and they consistently came up with different values. WMI returned 69 MB and SystemMonitor returned 66 MB. I ran it multiple times and got the same values each time.
Task Manager shows one Excel process with 31 MB used.
P.S. Kevin, you can tweak the SQL in the WMI query however you like... such as adding "where name = 'EXCEL.EXE'" to just get excel processes.
Well, it's not necessarily just a few meg. Both of the methods mentioned in this thread returned values that were more than double what task manager reported. That's a pretty big discrepancy. It'd still work just fine for your purposes but I'm a little curious why the difference is so huge.