From your post I can already tell you are not intelligent enough to create your own server software (this is not meant as an insult).
But to do so, you will need to:
- Download the DO Client
- Extract the source code from the DO Client
- Get the packet formation and the data transferred from each packet from within the source code of the client
- Use this information to create a software which will react upon packets from the client and create new ones to send back to the client
- Find a way to hack the client into connecting to your server software instead of DO's servers (Easiest way is to proxy a web browser, modify the maps.php so all server IP's are 127.0.0.1)
Bob's your uncle. It's a good years worth of work if you want a fully functional DO server like the ones you play on today.
~deHackerOwnz~