FET footprint in ADS momentum

I am drawing the layout of an amplifier in momentum and the transistor I am using does not have a built in footprint for layout. I am trying to draw the footprint and have drawn the required solder mask etc. but the only problem is how do I insert the pin points (i.e. wat appear as green dots similar to a transmission line point where ports are connected) as shown in built in layouts?
any help would be appreciated coz I am on the last step of my project and have to submit it soon.