There's no requirement for a point on the UV map to refer to just one point on the mesh, or even to any point on the mesh. You can have as many overlapping maps as you want. Consider if you make your own prop, say a hollow square tube by joining four Poser plane props together. If you don't remap it, the texture will repeat on each face. You can get this effect in UVMapper. Once you've selected the bit you want on a separate map, maximise it, then hide it so you can work on the rest of the figure.