Yes, you do add a SerialPort control, either from the designer, or in your code directly by creating an instance of the class yourself.
The SerialPort class has properties which allow you to set the port, as well as the communications parameters such as Baud rate, BPC, Parity and suchlike which must be correct in order to talk successfully to your specific device:
SerialPort Class (System.IO.Ports)[
^] - the link incliudes a basic example, but I'd strongly suggest that you "prove" teh communicatiosn via Hyperterminal or similar before you start coding. That way you at least know that the communications parameters that you think should work do, and that you can talk bidirectionally to the device before you start adding teh comlication of code that you don't know works either!