Modding tools for the original Divine Divinity are highly unlikely. There will be modding tools released for the upcoming Divinity: Original Sin
, though. As a test someone at Larian recreated much of Aleroth in the new game engine, and in one of the kickstarter videos they mentioned there could possibly be an official remake, or if that doesn't happen they could release some stuff to help a fan made effort.
The first video showing this was in the Kickstarter update #28
, or check it out on Youtube
. A couple minutes was shown near the end of the live Twitch.tv
kickstarter countdown (about 3h 53m into the 4h 16m video).
Welcome to the forum.