Hi Wim, if you have vertices in Blender in the spots you need, you could transfer those over to Moi. Export those as polygons to an .obj file and then use the OBJ to 3DM wireframe converter from https://moi3d.com/resources#Obj23dmWireframe_converter and open the .3dm in MoI.

You can also set up blending between shapes in MoI by building a surface between the hexagon and circle or ellipse using Construct > Loft and then use Construct > Curve > Iso to extract an isoparm from the middle of the surface. There is also one of Max's plugins cmorph that can automate that:
http://moi3d.com/wiki/MaxScriptArchive

- Michael