This would be a pretty big task, and quite beyond my modding abilities (stumped for three months about how to install mods, but I've got it now).
Basically, this would be a mage only thing, but when you get the planar sphere back to the prime material plane, the engine gets broken or something, and it can't be used any more. The mod would involve some way to repair it, and then travel to other planes, or maybe even other campaign settings.

Cool. Here is a way to incorporate that Dragonlance mod to BG2.