Prior to 10.7 (Lion) Apple did provide support for binding PCs to a 'Mac Domain' because in those earlier versions OS X Server acted as an NT 4.0 Domain Controller. With Windows7 Microsoft removed all support for NT 4.0 Domains as explained here:
In a nutshell you can't do what you're planning to do. You can however access shares created on OS X Server from a PC. Maybe you should rethink your plan?