Mecanim position specific bone

Hi, i need to control specific bones with Mecanim, something like IkTargeting but also for other bones like knee or upper spine etc. Bones which are not in AvatarTarget. I am a bit confused how to do that if its even possible. I can easily control hands and feet with IkTargeting but i need to be able to adjust with target any bone's position/rotation. Is there any way to access humanoinds bones and control them ?

Thanks for help