make a bitmap / video composite with ffmpeg?

hi there,

i need to make a little "content" editor in as3 which will do a layout of some text, bg image and a rotated and scaled videoclip. the output has to be a videofile.
so far i wanted to generate a bitmap in as3 itself and also create a configuration file for the videos position scale / rotation and x / y in the final composite. and then have a backend binary generate the final video from the input.

can i achieve this with ffmpeg?
or is there any other solution?

platform must ne windows

thanks!

anyone have an idea...?
thanks