ansoft hfss design 3d manual

Hi all
I have some 3D objects that creadted by AutoCAD.
I want trnsport these objects tO Ansoft HFSS, but I don't know.
please help me.

here ur request hfss 10,hope help u
../imgqa/eboard/EM/EM-0daq4sioreq.jpg

Thank you
I draw a box on AutoCAD and save with *.dxf extension.
In the HFSS I import this file, but HFSS not accepted.
plese help me more.