Last hybrid I rigged was a long dress.  It was modelled and grouped from the hip up the same as any conformer.  Below the the hip was a single group "skirt".  I rigged the the hip and up the same as I would any other confromer.  The skirt group was left unrigged.

The model is conformed to the figure (BVH's Angela in this case) and then taken into the cloth room.  The skirt group is clothified and the cloth simulation affects only that part of the figure.