Has anyone successfully used PTF with an externally controlled browser window?

While I am able to record a test that launches an external browser window that handles cc payment, it fails with "Object not found in the page, or the access is denied to the Frame." when PTF tries to set the card number: Text -> Set_Value -> name=card_number. I also tried Browser Get_Active but PTF does not seem able to identify the external window. Any thoughts would be appreciated! Thanks