BG2EE Request Thief/Mage/Cleric

Hello,
Not exactly sure if this has already been done or even where to post it.
If it hasn't already been done, would it possible for someone to create a Multi-Class that combines Thief/Mage/Cleric. FMC, MC, MT and CT exist so I don't see how TMC would be game breaking and infact I'm of the belief that it should even be in Vanilla.
Any help/advice would be much appreciated.
Cheers,
Kylu