Periodic structures and ABCD matrices

I am trying to derive an equivalent circuit for a differential stripline routed through a pinfield. (Please have look at the attachment).

The line has been simulated with HFSS and I got S parameters for up to 100 GHz.

Using de-embeding in HFSS, I hope to get S paremeters for each of the segmetns of the line, and than export them into spice, to simulate it in time domain.

Questions:

1.How do I draw schematic in Spice to connect a cascade of few 2 port elements (not 4 port, as they are differential S parameters), in order to get TDR and Eye diagram?

2. Has anybody got an example how to analyticaly calculate response of a series of ABCD matrices, each representing a part of transmission line?

Thanks :D