Adding something to the editor window

[Bellinis]

Hi vb people!

I want to to add a javascript to the page that will make it possible to insert special characters in the message window. Therefor I would like to create a new box below the message area in the editor window. If you look at the attached picture, everything will be clear.

I've tried to edit the newthread template to get the new box below and above the <!-- / message area -->, but that failed.

I see here on vb.org this window is also slightly different from mine, so I guess it should be possible to edit it somehow. I hope someone can help me out here.

Any help appreciated.