Select Serial Port Com number while simulink running

Hi

I am recevieing data from Serial port....since I am going to convert my simulink model to a standalone .exe file and send to another person, I want an option to show a drop down list in the simulink model so user can select the correct COM port number and after that click a "Connect" button to enable the rest of the simulink model and process..

but there is no option to assign a number or name to serial configuration.

How can I do that?