Inductor Lumped model extraction

I have simulated a one port differential on-chip inductor in HFSS. I need to extract the lumped model for this differential inductor. Most of the inductor designs have 2 port single ended S-parameters and its easy to extract the lumped model. The problem is that I need to excite the structure differentially and the only way I acn do it in HFSS is single port. Can I extract the lumped model through one port differential S- parameters (icluding parasitic capacitances). Can somebody tell me how to do it or guide me to the right literature. Thanking in anticipation.