Hi to all, this is a conversion from subdivision surfaces into Nurbs with Moi3D and the idea behind the sharp edge is substantially the splitting of faces, or the edge do you want to be sharped, because Moi3D has an option in SubD config that make the open border as a corner, but I made many examples for many cases that cover most of situations, but modelling with Blender helps, with the visualization of the edges creases to preview the final result.
I attached the source file of Blender and the obj exported from Blender, without apply the modifiers.

Blender geometry



Moi imported surfaces and solids.