Question : IP address port?

I don't understand how to set up the port that follows the ip address (i.e. 192.168.1.102:8093)

If i want to Remote Desktop to my remote computer from home, through a server, where would i set :8093 on the remote computer or router

Through a domain server (i.e. 192.168.1.102) i want to access a workstation which has an ip address of 192.168.1.98.
How would i do that? Do i have to use the port number? Where do i get this port number and how to set it up?
Thanks

Answer : IP address port?

Usually, you change the port a program listens through inside the application itself, through the configuaration of the app.