FCPX - Tracked Picture-In-Picture with Perspective for Video

Hi All,

Sorry if I haven't explained this properly in the text below but.... do you know how to create a Picture-In-Picture with tracking & perspective for video.

For example, if I film a street sign as I walk past it and keep the street sign in the centre of the video frame, the perspective of that street sign and any words/pictures on it changes as I walk past it. I already have the "Pixel Film Studios Auto Perspective Tracking" plugin so could easily overlay the street sign with a picture whilst retaining the perspective, but this plugin doesn't allow the use of video footage as the Picture-In-Picture.

How would I change the street sign to have a video clip on it whilst retaining the tracking and perspective of that (Picture-In-Picture) video clip?

Any help/advice or recommended plugins would be greatly appreciated.