As far as I know from what I have found, I believe that you would have to upgrade your license to prove that you have enhanced your skills in order to take the course again. I am going tomorrow and I do not have my license, and the recruiter said I would have to get my private license in order to be eligible to take the course again.
It seems that the best move would be to make sure that you put off actually getting the formal commercial license before going to the ASC, and if it happens to go bad, then you will not have to do too much to get the commercial and be eligible again (after the year wait).
However, I am not in the forces yet and I may be way off on this, so definately talk to a recruiter.
I also think there are some posts on the site about it, so just try different searches until something good comes up.