HELP! Transient on a microstrip line with holes

Hello all,

I would like to know if somebody of you guys know how to simulate in time domain (transient) the response of a microstrip line with holes when it is excited by a pulse with a duration width of 0.05 ns

I tried to do it with Ansoft Designer and HPADS but I can not, since I don't know how to simulate a hole on the microstrip line in the schematic window.

I will appreciate all your help in advance.

Luis