clamped surface with RhinoSrfPtGrid Method or RhinoSrfControlPtGrid

Hi

I want to ask how is the best way to make with VB a clamped surface.

There is a command in Grasshopper "surface from points" and you can choose if these points should be vertices or interpolated points.
I want to build something like a patch with G1,G2 continuety to other surfaces. And I have the idea to transform the edge-curves into clamped controll points and compute the second and third inner rows of controlpoints, with the normal-informations from the surfaces.

I think this will work, and I will be able to manage this, if I would know, how to create a clamped nurbssurface? can I use for that "RhinoSrfPtGrid Method or RhinoSrfControlPtGrid" with the manipulation of the knot-vector like in the case of nurbs-curves?

How are your thinking about this idea?
Did your know another way to reach the goal?

carsten