You can try adding PagePopup's class name to
MSAA or
UI Automation to make TestComplete recognize more objects. If this doesn't help, please post here at least a screenshot of this PagePopup window.
As for supported controls, you can find the entire list of the controls
here. Even if you don't find the controls used in your app on this list, it doesn't mean that you cannot test them. Read the
What If My Control Is Not Supported? section of the article I mentioned earlier to learn more about the suggested approaches.