Design choice using node.js and express and socket.io

I want to make a web app where every user can create a chat room that other users can join. I would like to have a main node server managing the rooms, and every time a user creates a new room, a new chat server should be started by the main server and it should manage the room.

My question is, how can I make the new server start in node.js and how can I manage it?