The winch controller is usually a set of four solenoid switches (consider them large relays) wired into what is known as an H switch, with the winch on the cross bar of the H - the hand controller selects two solenoids at a time so that the motor runs in one direction or the other - you can duplicate the hand control with a toggle switch - however - I would also suggest that you add a selector switch so that you cannot use the in cab control at the same time as the hand controller.
One last thing - some folks will recommend against the use of in cab controls - for safety reasons, I am simply answering your question and side stepping that discussion.