Writing to backbuffer using other methods

I’ve already asked this question on the beginner’s list but nobody had any idea. So I’m going to ask here, does anyone know of a way to draw part of your scene, say, using GDI or DirectDraw, and then be able to quickly blt (or something) directly to your RC’s backbuffer so that there’s no flicker? I’m needing to maintain graphics drawn with GDI or DirectDraw and then be able to merge that with my OpenGL rendered scene via blt or something. If need be, I could go the opposite way and merge the OpenGL scene with the scene I’ve drawn using the other methods. Whatever works. Does anyone know how this could be accomplished? Thanks!