thanks for your reply.
But,is there no other way?
Or maybe, I could sove it diffrent:
I got an car and a figure as characters on the scene.
The figure drives the car (he is parented with the seat).
In the car lays a prop (a nut).This is also parented to the car, cause I can’t put it in the scene, when the car door opens,(Frame 170) I have to put it in on Frame 0. ???
Now the figure leaves the car, goes to the backside, opens the doors and takes the nut out of it.
Here I want to change the ‘connection’ of the nut from the car to the left hand of the figure.
Maybe somebody got another idea to solve this?
I’m thinking aboout a ‘second’ nut- parented to the hand… ( cheap and dirty trick?) 
Thanks
Alex