If what you want is to enter text and have it permanently insert that text in the correct section, then you will need a server-side script to do that. PHP would be the obvious choice (although not the only one).
If you need help with that script, then you should ask in the appropriate area of the forums.
Do be aware, however, that while people will be willing to help you with a script if you get stuck, it isn’t appropriate to ask for somebody to do this for you. So if you don’t yet have the skills to tackle this, you might need to wait until you have learned more, or pay somebody to do this for you.