Hi contactor.
As shown by you, yes, you can define the ports 1,2,3 and 4 as you set - do this as follow:
For every port assignment you will need to pick up 2 points: 1 is at the ground and the 2nd one is at the lower edge of the PEC port metal lines.
You can simulate a 4 port model doing so.
Or, you can assign for every ports a (+) sign or a (-) - this will set a common-mode port and/or a differential-mode port - try to see at help CST provide - you will find excellent explanations.
Good luck,
IH