Need business visa for Hong Kong

Dear Friend
I am a Pakistan national running my own LLC company for last five years in Sharjah. My designation on visa is partner, now i want to go to Hong Kong for business, so kindly tell me how to get the visa for Hong Kong, I have good business links with companies in Hong Kong and they are ready to send me invitation letter but first i want to know the requirments, so please guide me.
Best Regards
T.Dar
050-9517127