IAccessible interface and automated testing

We're evaluating a tool called Ranorex that we might use to do some automated testing of our application.  It works on widgets that implement Microsoft's IAccessible interface.  In particular it would be useful for us to get this working with PropertyGridItems (which we use extensively).  It doesn't seem to work out of the box though.  I see that you've got CXTPAccessible in the class hierarchy, but do you have some advice on how modify our code so the PropertyGridItems will work with Ranorex.  Or if there is another tool you suggest we try instead that would be useful as well.