PointCloud cast to C++ object

I changed the initial Rhino Plugin and am able to pass pointclouds back and forth between Python script and C++ DLL using the serial number of the pointcloud. The details are in the listings of my scripts (Python and C++) here:

Not sure if this helps you as this is from a Rhino pointcloud in Python using Rhinocommon to a Rhino pointcloud in C++ using the C++ SDK. You want to go from a .NET pointcloud to C++. Could you do this by first transforming the .NET pointcloud to a Rhinocommon pointcloud in Python and then going to C++ land?

I like the combination of Python & C++ DLL because I can use all the rs.stuff and Rhinocommon in Python to interface with the user and create Eto Forms and then get the fantastic performance of parallel execution inside C++ to do the heavy lifting. Now I can work with 6.6GB pointclouds with 1/4 billion points in under 15 sec for import, combining and coloring which is a 7th heaven for me.