How to position item in hand?

Hello,

Probably this have been asked a lot of times before, but I still couldn’t find a well written answer to my problem. Currently I am trying to add a flash to one of the sockets. For idle it seems to be okay, but when my character starts running or doing other animations my flashlight socket gets misplaced then.
Reference pose example:

Walking example:

Is there a way how I could set a different socket position for each animation?

You should only need one socket. I’d imagine your problem is likely your choice of bone to parent from.