I would like to ask about hand position (supinated, pronated, neutral) and affect on heads of triceps (long, lateral, medial) can you give me some advice? Or hand position do not affect on muscle activation in different portion of tricep heads?
Wrist position has no direct effect on triceps extension. However, it does have an effect on shoulder external or internal rotation. With the supinated version, the limiting factor is the wrist since it is in a weakened position compared to the pronated grip so you'll be losing strength because of it.
As for the pronated grip, it's harder to keep the elbows in as you have to get in a semi-supinated position to keep the elbows in internal rotation. I would rather focus at varying elbow position and strength curves, from the hardest (frenchpress) to the easiest (pressdown).
Very mild change --- as Eric mentioned, the triceps are elbow extensors, there is no pronation or supination involved with triceps (unlike with biceps exercises).
That being said, some people "feel" an exercise in a certain area more, which could possibly indicate greater activation of a certain pool of fibers for that individual. Overall though, I wouldn't lose much sleep over it. Agonizing over this would be much less productive than just getting stronger at a variety of different meat and potatoes triceps exercises.
Finally, I will add that many popular triceps exercises wreck people's elbows, not because the exercise is bad, but because they lack the shoulder mobility to keep the elbow hinge in a straight line with the path of resistance. For this reason, I favor heavy neutral grip bar pressing with a lot of chain or band accommodating resistance to overload the lockout, and then for the high-rep stuff, you can't beat the multi-directional ability of a good pulley system. Cross-pulley triceps extensions from a wide variety of angles have proven to be VERY elbow friendly and there are almost endless variations based on the pulley position and your body position. Good luck!