NYC lets you browse for cookbooks across all network drives. Select File... Open Cookbook... and use the drive list selection to find cookbooks on drive on the network that you have mapped. To map a network drive, use Windows Explorer, Tools…, Map Network Drive… To be able to select unmapped drives, you will need to first set NYC to use a standard Explorer-type window for opening cookbooks (uncheck the NYC “annotation” option in Tools… Options… Cookbooks…).
So just keep your cookbooks on one computer's hard drive, share that drive to the network, then use NYC on any networked computer to open the cookbook on the shared drive. A couple important notes:
1. NYC is not a true network app, so you cannot simultaneously access a cookbook from two different computers.
2. Any computer using NYC to access a cookbook on a network drive must have read AND write access to the network drive, or NYC will fail with an Error 75 (read only file) message.