Jeyshankar,
User-exit IWO10020 should help you. I have documented the use of the same. You can apply this to your requirement with the help of ABAPer for code modifications. I think this is the only way.
Automatic Tasklist transfer to PM Orders: User-exits IWO10020, 21 ( You can see already the codes here used IF condition based on an Order type ).
The main subject of Configurable tasklist using dependencies in characteeristics, you must be already knowing . This also has been documented Configurable Tasklist (You might have already gone through) .
Good luck
KJogeswaraRao