Sorry if it is possible right now and I dont know how to do it, but if it not possible I vote for that possibility.

If it is possible just tell me how I can adjust duration of some midi part.
Let say I have 2 bars with 4 quarter-notes each (2 x 4 = 8) and I would like to get 3 bars with same 8 quarter-notes shifted in time to fill 3 bars.