QRs (Queen's Reglations) are the bible and I think I'm right in saying that they will say that you cannot wear your medals other that in uniform. Yes, you could/might get away with it but do bear in mind that if you're seen or photographed you may find yourself in front of the CO. Forget the CC, speak to your Adjt - it's his/her job to advise and police the rules and more importantly, he/she has the ear of the CO.