sweep problem

I want to create a brep that starts from the left surface (section) and ends in the right surface (section) and follows the planar surface below (which is the base of the brep). I tried sweep2 component using the two vertical surfaces (or their perimeters) as sections and the 2 curves at the edges of the base surface as the 2 rails, but it didnt work. I also tried the sweep component using the same ingredients and the middle surve as the rail curve and nothing happened also.
any suggestions??

thanks!!!