If no one else replies, I'll scan an image of how to wire it when I get home. No scanners at work.
You will need a DPDT switch set up to reverse the DC motor. Center contacts are wired to each side of the motor. End contacts are crossed. In other words the top left contact of the switch is wired to the bottom right contact. Then the Top right contact is wired to the bottom left. Then each side is wired to your battery, one side for plus the other for minus. Do not have theses leads shorting! . I'd use a roller micro and a wheel on the servo used to control this. Make a cutout on the wheel so that it ramps the switch on or off depending on the servo direction in the center of it's travel. Then at each end limit position of the jackscrew wire a lever arm micro normally closed, so that the switch opens when the jack screw is at it's maximum travel. Zap you have it using 3 switches and a servo.
John
Man I wish I could spell!