For the case that somebody likes to know how I finally implemented the PIP stuff, here it is.
- Render Movie as BMP for the desired views.
- Crop the images for the small film (I used IrfanView - Batch conversion/rename).
- Copy the small images over the large ones (Login to see the attached C# program).
- Make an AVI with VirtualDub.
- File - Open video file : select the first picture of the series
- Audio - No audio
- Video - Frame Rate - Change frame rate to (fps): 24
- Video - Compression - DivX - 1 pass - quality based
- File - Save as AVI