'Blending' using the Accumulation Buffer ?

Ok, i have a background and one big morphing surface in front of it. Now i want that the background shines a little bit througth that object.But i dont want that the object itself is somewhat blended (means that the polys further away are seen through the polys nearer to the eye).
My idea was that maybe this could be the job for the accumulation buffer…render background -> put in buffer ,render 3d object (in opaque) mode and add it to the acc. buffer and then transfering the result to the back_color_buffer -> swap
Is this idea that i haven`t tried yet a good one, is there a better way or can you give me a good proposal how to combine the either pics in order to get the desired effect i mentioned before?