Mogg sell a DSI-C which goes from DSI (T-thread) to Cmount lens. This may be what you need.
http://moggadapters.com/astro/adapter.asp
Also ScopeStuff have the device:-
http://www.scopestuff.com/ss_t2ca.htm
Regards,
Tony Barry
(not affiliated with Mogg or scopeStuff)