How early I can get a Visa to join a training in hong kong?

I am working for a foreign bank in Bangladesh and got an invitation to join a training will be held in hong kong. Now the problem is I have only 12 days in hand but all papers are ready. Please advice me is there any chances to get one for hong kong within these 12 days? And how? Matter most urgent!

Also please do let me know whether I should apply for F type to join the training? I am also requesting you if possible, please attach a application form which is suitable for my case?
Thanks in advance for co-operation in regard.