Copy location to 2 object problem

Hi everyone,
i’m total noob with blender. I use a 3D cad system to engineer products and I wanted to animate it with blender. I’m very enthusiastic about blender but i have a problem that keeps me from finishing the model for the last 3 days.
I have 3 objects , 1 is the bridge, 1 is an intermediate piece and 1 is the target. The intermediate piece has to be copy location to the bridge but also a single point has to be copy location to the target. Furthermore the target shall be totally fixed in position which I also cannot solve. Please help me how I can copy loc 1 part to 2 objects and how to fixate an object in space. Thanks for you help in advance. Marcel

Please supply a simple demo scene blend so we don’t have to try and interpret what you have written.

Clearly annotate to make it clear what you want you want to do and what issues you have with your current rig