Smudge, civilian qualifications I can't vouch for, but you are able to join various Institutions, which if you trawl through the threads on Sappers, you will find (I think it was "So, are you a member of an Institution" or something like that) I'll confirm that with you after this post. Also, I assume you can contact your Trg Maj (are you in 101?*) who should be able to put you right. Failing that, get hold of BEW (who qualify you) who should be able to help.
DSO qualifies you for f__k all in civvy street. Just means you can initiate explosive without, hopefully, blowing your or someone elses arse off. Get real ! Look at the IExpE website for civvy explosive engineering requirements.