I faced a similar problem & bought a Winch Remote Control on EBay for about £20. They're sold for 4WD/ Agricultural winches but work perfectly well on a boat. Comes with 2 hand controllers, which aren't waterproof but have served me well. Wire the relay supplied to your windlass contactor, which on my B39 is behind the control panel. You can then operate the windlass from anywhere on the boat.
Lexmark sell a similar set of kit for about £200!
John