DXF Polygon Mesh to IGES Surface ?

Hi Group,

I have a DXF
file(http://www.anderswallin.net/wp-content/2004_11/learke_mk4c.zip)
with surfaces represented as polygon meshes. This file does not import
correctly or at all into a number of cad or cam programs... so I want to
convert the surfaces to IGES or some other format that I know my cam
program understands.

It opens OK for example in Rhino, but when exporting as IGES it says
"polygon meshes not supported", and the IGES file ends up containing
nothing...

thanks for any answers,

AW