In Daz studio 4 Is it possible to copy the bones from one figure and then paste them into another?
Up to a point. It depends on whether it's a legacy (Poser parametric) rigged figure or a TriAx figure - for the former you copy into the Figure Setup pane,s wap the geometry, and create your new figure with the Modify selected box checked; for the latter you use the Transfer utility. However, those copy across the whole skeleton rather than selected bones, which may not be what you want. Also note that there are limits on what you can do with the result - you can't use a DAZ figure as a donor to make a rival base figure, though you can use it to make clothes or hair for the DAZ figure, for example.