Hi eric - it's unfortunately quite difficult to build a surface directly to a sort of undulating non-planar path curve like that particularly when it has all sorts of sharp cutouts in it...

The closest thing to a ready-made tool would be Rhino's Patch command, which can fit a surface to a set of sampled points. But it tends to be hard to get the surface to very accurately hug to such a detailed path.

Usually it's better to build a larger extended wavy surface by something like loft or sweep to define the overall surface shape, and then trim that surface with a 2D plan view of the detailed outline, rather than trying to directly surface a 3D waving outline itself...

Can you maybe give a little bit more background information on how the heights of the non-planar outline you've got there have been specified? I mean does it have to match up with other pieces or .... ? I'd mainly try to think about how to build a surface using a more simple layout of cross sections in something more like a 4 sided layout.

Anyway as a first stab try the Patch command in Rhino, and see if it will fit a reasonable surface through that.

- Michael