Surface from arcs

[Enoughie]

Hi,

I'm trying to construct "saddle-like" surfaces by attaching four arcs together and then applying to them the Surface modifier (similar to the images attached). The problem is that to create a surface you can only have 4 vertices for each surface, however each arc in itself has 4 vertices (so that makes it 12 vertices for the spline). The question is, is there a way to make arcs with only two vertices (ie. at the sides of the spline) without losing the detail of the curvature, or is there some other way (applying some modifier perhaps) to produce a surface from a spline with more than 4 vertices?

[Anonymous]

Draw your shape as a closed spline, convert the verts to Bezier Corners and adjust te handles to get the shape you want.