Paris Museum Pass

I cannot say Paris Museum Pass is not sold in Hong Kong, but I have never heard this before. If you really want to buy it in Hong Kong, you can contact Maison de la France. If there is point of sales in Hong Kong, Maison de la France will be the most suitable place of selling it (Tel: 2815 5877).
In Paris, there is several places selling the pass. There is a Office de Tourisme in Gare du Nord, you can buy the pass there. Also, you can also buy the pass in FNAC in Champs-Elysse.
Actually, I will recommend you getting it in FNAC.... Gare du Nord is too big, it's hard to find a booth there...
http://www.parismuseumpass.com/en/pass_points.php?categoriepointvente_id=1&typepointvente_id=32