Many fingers are lost that way. As for the animations and rigging themselves I would start by exporting the arms with the skeleton which would be Human_Male_FPV which is a skeletal mesh. Then import into your 3D package and from there begin to do you rigging and animation for you custom weapon. Note this will have to be done for the 3D person as well, same scenario. If you only want to do one animation custom, like the unsheathing of the blade then keep the skeletal hierarchy named the same otherwise the other skeletal animations will not work. I know I just word vomited on your forum post but if you have any questions you can PM me.
As for animations and rigging the internet holds all the keys, I plan to do a lets rig a dino or character but that is down the line still.