Hi Marco, yeah MoI does not attempt to read polygon mesh data from DXF files, it can read LINE, CIRCLE, ARC, POINT, POLYLINE, LWPOLYLINE, ELLIPSE, or SPLINE entities out of the DXF file.

One possibility would be to use a mesh conversion program to convert the DXF file into an OBJ file and then use the OBJ to 3DM wireframe converter from here:
http://moi3d.com/resources#Obj23dmWireframe_converter

- Michael