A friend is doing a short film about a character doing a live webcast and wants to do a shot where the audience POV starts on a view of the webcast (YouTube or Justin-styled) and then pulls back to reveal the webcast screen on the laptop in front of the character.

He's thinking of doing it in post but I figured it would be better to actually show it on the laptop screen for real, if it's possible. (Although now that I'm posting, I'm unsure on refresh rate vs shutter speed. The camera is Sony F335.)

Is there software that could throw the laptop's own live webcam feed into a larger video pane?