The best thing you could do is not mention your PPL. Military flying training is very different from civilian flying training in that you will be expected to be able to operate a complex aircraft safely, to its limits in possibly hazardous conditions.
As a PPL you only need to be able to take your granny for a flight and not kill her!
Best way is to be an attentive student and learn with no pre-conceptions. You may well have formed some bad habits that are fine as a PPL but will get you killed in a trice when playing with the big boys. Your experience may help you initially but keep your PPL under your hat and let people think that you are just a good learner. You will very soon find that the training will become the most demanding (and most satisfying!) thing that you have done to date.
Bon chance!
Mog