Your question deserves an answer. Sorry for Ecomodder being so unwelcoming.
So yes
anything is po$$ible.
The helpful part would be how. I have no Idea. I suspect it would involve an Aurdino or similar processor board.
For the 4-speed auto and for the intended overdrive; what is the control mechanism? physical shift rods would have a different solution as compared to, say, CAN Bus messages.