Just select the hamd joints or locater depending on what you used and middle mouse to the wo what key you want to copy say at frame 12. then its just a matter of keying the keys in that postion.
The walk cycle i did in the vip section goes through it all....
I am enough of an artist to draw freely upon my imagination, knowledge is limited, imagination encircles the world. (Albert Einstein)
https://www.artstation.com/kurtb