There are a few options to do what you'd like.
You can export to Rhino through the File-Export menu. Rhino can save
the resulting file as IGES, STEP or any number of common CAD formats.
Rhino has a free demo available for download which can save 25 times.
However, it is probably easier to work directly from a STL file. VSP
can create STL files in three ways -- two are appropriate for rapid
prototyping. First, use CompGeom to generate a triangulated mesh of
the geometry, then use the File-Export menu to get a STL file.
Alternatively, use the CFDMesh menu to generate a triangulated surface
mesh.
It should be very easy to feed rapid prototyping machines from VSP.
Give it a try and let me know if you have any questions.
Rob