Just adding a bit to ElisaZ's post...
The FCC says (in Section 15.202 of the Radio Service Rules) that you cannot configure an AP to operate outside of the US regulatory domains with a controller that resides inside the US. When you purchase a controller for use in the US, you cannot even configure a regulatory domain other than US. Israel is the only other country that has such restrictions to date.
So, if your controller is in the US, it's locked to the US regulatory domain. In order to manange RAPs in the Chinese regulatory domain, you'd need a RoW controller and, legally, it needs to be installed outside of the US. Alternatively, you could connect the RAPs to your US controller and use US frequencies and power in Hong Kong.
Technically, you're then breaking Chinese regulations and law. The Chinese regulatory domain only uses a fraction of the 5GHz channels, uses more 2.4GHz channels, and their power reguations are all different from the US. I really don't recommend doing that.