Send Message over network

I have a program running on a regular PC waiting for input. I need to take a custom mobile app and have it send a simple text string to that PC (I would specify the IP address of the server)...

Basically, on the mobile app, a user would enter a simple number... the number (in plain text) needs to be sent to the server via the network.

What's the easiest way to do this?

Thanks.

Look at the system.net namespace, and use a socket - presumably the server is listening on a port?
Create a socket, and connect to your IP address using that port, and then you can send and receive