Backbuffer Access in D3d ?

Hi guys, I''m converting my 2D game''s graphics system from DirectDraw to Direct3D and, for the most part, it''s going rather well. But I''m getting a headache trying to get a full screen bitmap on the back buffer using textured quads because of the powers of two and square size bitmap limitations. So can I access the back buffer memory and do a DirectDraw style blit ? Is that recommended ? I guess I can break the screen down in to power of two squares but that''s going to be a lot of calls to SetTexture unless I save a 1024x1024 bitmap which is a waste of memory. Also, most of the screen is the play area which gets the textured quads drawn over it so it would be great if I can start off with the full screen image (the borders, score and status area, etc.) on the back buffer then render my textured quads on top. Does anyone have any ideas ?