Dave,
The truth is it is easier to fight back before the disqualification is issued. You could have got a drink driving lawyer to present a good case for you and either avoid the ban or get it reduced in the first place but after a driving ban has been imposed, it is more difficult to do anything about it. Of course if you are attending the rehab course for drink drivers, you can expect upto a quarter of your ban lifted but other than that there's nothing much that you can do about it. For driving disqualification less than 2 years, you are expected to serve the full term of the ban.
As I always say, if you need your driving licence badly, then it is probably worth speaking to a drink driving solicitor/lawyer and see if they can help you since they are the experts in this field.