I am not experienced with Rational Robot, but I am currently exploring the topic of automated GUI testing.
Here some basic information, which you may already know, but if you dont, they may help.
Almost each basic graphical object in Windows is a registered system object. If you have access to Microsoft Development Studio, run Spy++. You will see a tree. Right click on any of the branch. If there is a “highlight” position in the pop-up menu – choose it. It will highliht the right object. Try to run spy with Forms. See if it helps.
As for windows internals, read Petzold “Programming Windows”, first few chapters about windows basics.
Also have a look at source code (in C) of Win32::GuiTest perl module. It will also give you some insight how to deal with windows GUI objects. If you are more familiar with perl, install it on your machine and experiment. There is a yahoo group devoted to this module perlguitest. There are some pretty valuable posts there.
Then go to Robot and check if it offers a possibility of reading objects of the specified id
General warning: Windows and tools like Rational, QARun make promisses that life with them is easy. And they appear to be easy on the first glance. But if you want to do anything that is not foreseen by one of their Wizards (which is ALWAYS, ALWAYS, ALWAYS the case when you do some serious work) life becomes difficult. It is not my intention to scare you. Just be prepared that getting from Windows what you really want is not that easy as Microsoft is promosing.
I hope I did not scare you and I hope my post will help you. Good luck.