Node.js cluster passing connection to specific worker
<p>I have my multiplayer game based on socket.io library and i want to scale it on multiple threads. I've learned that node.js have cluster module to handle multithreading. 
My game world is made of multiple zones and I want each zone to be handled in it's own proccess. I need a method to pass user's socket to specific worker, so user could move from zone to zone. 
I've read in node.js docs that cluster module uses round-robin method to pick worker for every connection. Maybe there is any workaround to manipulate connections?</p>