Hi YHWH_777, see here for some info on polyhedra:
http://moi3d.com/forum/index.php?webtag=MOI&msg=5037.9

There's a link there to a web site with some various premade ones in 3DM format (I don't know if the particular one you need is there, possibly not), and also some links to some tutorials on construction techniques for making stuff like that from scratch.

Also if you already have what you need in Blender, the easiest way is probably to export to OBJ format and then use the OBJ to 3DM wireframe converter from here:
http://moi3d.com/wiki/Resources#Obj23dmWireframe_converter

That will take the OBJ file as input and then as output generate a 3DM file that has a line segment for each polygon edge. Then that 3DM file can be loaded into MoI and you can create surfaces by selecting 3 lines that make up a face and using Construct > Planar.

- Michael