Can HFSS define eps/mu a negative value?

Can HFSS define eps/mu a negative value? How to define it?

I need use HFSS to simulate left-handed materials, may I ask anyone can tell me how to do it?

Thanks a lot!

No, it can't!

It definitely can. Check out http://www.ee.ucla.edu/mwlab/posters.html . There is one about LH materials simulation using HFSS.

I'm optimizing a design in hfss using a negative epsilon right now. It defintely can.