Hi everybody, so I've just made it tghe way I wanted it to be:
First took FSIUPC options to use mouse middle button as mouse look.
Second, I took Logitech options program (it allows to make mouse profiles for specific programs) and set side buttons in my mouse (Logitech M510) to be used in Prepar3d as middle buttons also.
So now I am looking by the mouse pushing one side button only, so I can use middle button wheel to set instruments in a cockpit, very useful to me.
Regards!