Set one server VI on the remote computer to LISTEN (create listener / wait on listener) continuously for one port. When it receive something, READ the string and see if it is the one that you are expecting. On your computer, set a client VI, which first CONNECT (open connection) to the remote computer (using remote's IP and port number) and then it SENDs a string containing the command.
Hope it helps.
p.s.: Uppercase words name the Vis that you should use for this application.
