A tool that was quite popular in ancient times. Well, 20yrs ago. But, for what I saw, has disappeared for whatever reason?
Not sure if Microsoft has announced an "official" successor to it ...
is a suite of 22 programs—one Control Spy program for each Windows common control. This article covers how to use Control Spy to gain new insight into the common controls, including the Microsoft Internet Explorer 4.0
controls and the latest updates to older controls.[More]
Seems to provide its source code, so probably it'll contain some info on how to capture difficult-to-capture controls.