Help me draw a rod in HFSS
use a torus and cut it into half
You might also find the "connect" feature useful. With sweep around an axis you can create curved cylinders.
either torus or sweep both the cases the shpae is not conical. both the end have the same cross section
Does HFSS have a "loft" option that allows you to select two object faces and create a solid between them? I don't have access to HFSS at the moment, so I can't check.
I know that MWS has that option as shown beginning at about the 3:00 mark in the video http://www.cst.com/Content/Showroom/03/03.html.
If HFSS can do this, then you might have to draw evenly spaced cross-sections along the "swept" curve and loft between them to get a smooth cone. If the number of sections is very large, it would be much easier to accomplish with a VBScript.
Sorry if none of this is even feasible.
You can easily draw it in pro_E and import it into HFSS.