Just download and play with the tool. The tool detects the VIs currently in memory, and you can select the one you want to see in the control that reads "VIs in Mem". Because you have access to the source code, you can review it to learn the nuts and bolts on how it works!
The author, <a href="http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RPAGEID=261&HRedirected=True&HUserId=101_54000&RFORMNUMBER=6";>PJM LabVIEW</a>, has put a lot of effort in this excellent tool and I am sure he will be more than happy to answer any questions you may have (and even add new features you request, of course, if they are valuable and can be implemented)
