I can type chinese using jump dektop on ipad. If you can type chinese in your chinese windows, now you should be able to type chinese by switching language input method in remote desktop. Another possibility is waiting for iaccess hd to support external keyboard. I can type traditional chinese in remote desktop using iaccess hd with virtual keyboard. But I think iaccess hd doesn't support external keyboard now
As I mentioned in previous post, jump desktop is the best for using ipad with external keyboar and mouse (The remote control apps I tried are listed in the link above and these apps are almost the most expensive remote control apps).
I have make the suggestion to the author of btstack keyboard. If he can make the btstack wrok as apple official bt, then we may be able to use hotkeys such as copy and paste in jump desktop.