Some products do not come with hand presets, so you'll have to make
them yourself. You can also buy and use GMCC's plugin sold here:
For making your own hand poses, this is one way that I recommend below. I've given a logical order, but you can change it as desired. Skills used include: posing, multi-selection of nodes, and parenting.
Position the figure, especially the arm and hand how you want it. You
don't have to move the fingers and palm to the exact position at this point,
just get it generally as you wish.
Move the weapon into position. Put the hilt into the palm, etc. Again, this doesn't need to be exact right, but as close as you can do at this point.
Now pose the fingers. In DAZ Studio, you can multi-select fingers and bend them all at once using the bend parameter on the Parameters Tab. Continue to adjust the fingers and thumb and even the weapon until you have it the way you want it.
Parent the weapon the hand of the figure. To do this, go to the Scene Tab.
Find the weapon listed (This is a word, not a model). Drag and drop it onto
the hand (which is also a word, not a model). You'll see the weapon now
listed under the hand.
Once the weapon is parented to the hand, you can move the hand of the figure in the view port and the weapon will follow along.