where in hong kong can i hire a standing hoist for a disabled person going their on holiday?

Don't ask the hospital directly. In Hong Kong there are government-funded and private hospitals. You might end up going to a private hospital and having to pay a lot more than necessary.

You might want to contact HK Tourism for more information and hire/rental arrangements if necessary:

http://www.discoverhongkong.com/eng/trip-planner/hongkong-disabled-traveller.html

Just contact a local hong kong travel agent and ask whether they can arrange for you.

hiya, ask at the hospital in hong kong.have a great time.