Steven,
You cannot voluntarily go on the rehab course for drink driving as it has to be recommended to you by the judge who sentenced you. If there was no mention of the course, then perhaps it would not benefit you in any way. As you are probably aware, driving and drinking can be fatal and rules are tougher for learners because if they set out on the wrong path at the very beginning, then the future does not look bright at all for them. Therefore provisional drivers need to be more careful about going against the rules and if they don't worry about their own safety, then they should at least consider the harm which can be done to other people as well.