How to create a NetworkSrf or Boundary Surface in VB?

Hello,

In VB, I'm trying to create a surface that is "bounded" by a set of curves.   I can do it in Rhino by using the NetworkSrf command.   I can do it in Grasshopper by using the "Boundary Surface" block.  But I have not yet found a way to do this in a VB script.

For example, my VBScript to create the curves would look something like:

Dim example As New List(Of Curve)

Dim exleft As New Line(New Point3d(0, 0, 0), New Point3d(10, 0, 0))
Dim extop As New Line(New Point3d(10, 0, 0), New Point3d(10, 10, 0))
Dim exright As New Line(New Point3d(10, 10, 0), New Point3d(0, 10, 0))
Dim exbottom As New Line(New Point3d(0, 10, 0), New Point3d(0, 0, 0))

example.add(exleft.ToNurbsCurve())
example.add(extop.ToNurbsCurve())
example.add(exright.ToNurbsCurve())
example.add(exbottom.ToNurbsCurve())

C = example

Which gives me "curves" that create a square in Rhino (the actual script will produce something much more complex than a square, but basically a bunch of curves on the same plane).

My block that uses that script looks like the following image (it has a bunch of inputs and another A and B outputs that are not used in this example, but has a purpose in my real script).  

To make a surface out of the curves, I can use the Boundary block.   But I want to make that surface in the VB script instead

Any pointers?

Thanks.