now I have been granted my working holiday visa

i need to leave HK to validate it...but i have one problem, i have two passports. I came into HK on my british one, but the working holiday is granted for my aussie one, so if i go to macau or shenzhen i will have to leave HK on my british one, but then i need to come back in on my aussie one, however i will have the visa for macau/shenzhen on my british one, so they will be totally confused...like me right now

...has anyone else had to do this? or does anyone know the easiest way of going about it?
