Where can I short SHCOMP (Shangai Composite Index) with bitcoins?

796.com have recently added XinHua A50 Index:

'What is XinHua A50?
The FTSE/XINHUA China A50 Index comprises of the largest 50 A Share (shares in RMB only available for purchase by China mainland citizens) companies (full list) by full market capitalization listed on the Shanghai and Shenzhen stocks exchanges. “The A50 is the headline index of the FTSE China index series designed to represent the performance of mainland A-share and overseas-listed Chinese companies. It is an avenue for non-Chinese investors to gain direct exposure to large-cap Chinese stocks.” Based on SGX FTSE China A50 Index Futures, 796 Exchange modified the stock futures to suit Bitcoin trading purpose. To make it accessible for small investors, we changed the multiplier to 0.0002 BTC per index point and set the margin requirement to as low as 0.1 BTC per contract.'