Before you adjust the handbrake cable you should check whether your rear brake pads need replacing. Also, jack up the rear of your car and remove the rear wheels so that you can check whether the handbrake levers on the calipers are moving freely and 'springing' back when the hand brake is in the 'off' position. If one of these levers is sticking, the automatic adjustment for the handbrake will not work and you will get a lot of free play at the handbrake lever inside your car.
If you do find a sticking caliper lever, spray it liberally with WD40, remove the cable from the lever and then work it up and down with mole grips until it is free. If you pull the lever down, it should spring back up when released.
I have just carried out the above procedure on my 03 Ulysse 2 and the handbrake movement was restored to normal without any adjustment to the cable length.