Can you buy or retrieve tickets to Fujian at the Hung Hom train station ?

Yes, you can buy the train tickets of mainland China at the Ticketing Window, near Exit C, MTR Hung Hom Station, but to collect tickets which have been booked, you may have to go to a rail station in mainland China.

Please note that the above site only sell tickets to 150 persons each day, and each person can buy 4 tickets at most. You need to start early, and wait in queue. Or, you may book the train tickets through TravelChinaGuide. You can contact them through bookingtravelchinaguide.com. ;)