It can be done but it would require modification to the code and I don't think DongFeng would want to do that and I'm not up for it either
(it'll be me who modifies the file since I have the FTP access to the source code files).
However, next version of this software coming out very soon will likely have this feature or even if it requires code modification it would utilize plugins so that basic code doesnt need any changes. You can see a demo of some of the technologies coming in the next version here:
Until that time, you can try these things:
If you are writing something long, I highly advise that you write it in a word document. That will help you with two things: 1) spell check built in MS word and then you can copy paste the post into the reply box. 2) incase you hit reply and it doesn't go through due to a problem with the site... that would save you alot of time rewriting your post.
You can also use dictionary.com or answers.com to check certain words in no time.
I hope that helps!
Enjoy!