The fact is dont really think that rendering a view to a bit map is the answer...in fact i dont see how that would work at all for what you want.

The much easier way to do what you need is simply to make you pre-rendered background a texture, map it onto a flat polygon mmodel, and position this is such a way as to fill up the screen, and make sure you set ambient to 255.

Then simply put all your 3d models and stuff in front of this plane.. you will have to mess wiht it a bit to get it right, but there is no resaon this cant work the way you want.