I have done this on a baseball video that I did. The software that I used was ULead Video Studio Plus 10 although I think there is a newer version out now. The good thing about it is that you can use overlays and position them where you like on the screen so in your case you would scale down and place within the tv screen can't quite remember how much I paid for it but I think it was about £80.00.

Another piece of software that can also achieve this  is Adobe After Effect but this is a lot more expensive.

Hope the info has helped.

duchess110