Is it possible to have a change in perspective in P-in-P

[jparnold]

I think that I have got the hang of using the Picture in Picture video filter however I would like to have a change in perspective of the overlay (P-in-P) during the clip.
To better explain.
I have a video clip of a tour guide speaking with a sign on a wall next to her. The clip was shot at an angle of about 45 degrees to the sign. I then have a video clip taken of the sign which fills the frame and was shot at 90 degrees to the sign.
I have used P-in-P to place the video of the sign over where it appears in the first clip and then it rotates slightly (to allow for the change in angle) and expands to fill the screen.
It would be nice to be able to change the perspective where it starts as a small image and then the perspective change as it fills the screen.
I can do this with Mediastudio Pro but would prefer to do all my editing using X4.
I know that it is really only a nice to have but is there a method to do this.
If not I will add it to the wish list for X6.
Thanks