Can I add a parent to all the children in an animation tree structure ?

I made the animation for my arms which refers to the bones directly but now, I would like to make my arms child of my camera named "FPCamera" but the animation would be edited. My question is can I make my animation refers to "FPCamera/..." for all the bones (make them child of "FPCamera") in the tree structure of my animation ?

Thank you lot.