I was using the language keyboard for Chinese characters and just couldn't navigate the menu. I stumbled onto this app that I could draw the character with and then cut and paste to my message that I wanted. Thought I should share it here. I'm not at all connected to the app developers but it seemed to help me. I have a Z10 also and I think it's awesome. The app is called Flash Fingers Handwriting. Hope that helps. You can look it up in BlackBerry world.
Not sure if this issue has been resolved. I found a solution and thought I would share it. Go to input languages and select the third last from the bottom. Using this language input you can draw the Chinese character on the screen and the Z10 will display suitable options.