HK has a localisation policy,so as far as I'm aware there are no openings for expats at the moment.This could change if they get short of experience etc.
If you are already in HK why not ask the CAD and see what they say.The worst that can happen is No.They have relaxed the rules about expats,and some have changed over to local terms.Worth a e-mail to CAD in Queensway.Good luck