It is complicated by the fact that the division of the model into materials is not the same, so there are areas of victoria 4 that take parts of two separate maps from Genesis 8. This isn't just a matter of different polygons, the avaialble edges for defining different materials don't line up. In Daz Studio that is handled with GeoGrafts, patches of mesh applied to the base figure that have suitable splits so that the non-overlapping areas of the figure can simply take the maps 9using a nwe UV set) while the grafts handle the areas that need distinct maps, and put extra divisions in the right place. Poser doesn't have a graft equivalent, and i don't think it easily swaps UVs, so the reverse isn't really possible.

What you could do is create a new mesh in a modelling aplication that was the shape of Genesis 8 or victoria 4, but mapped and with surface divisions like the other figure. Apply the maps to be converted to the Gensis 8-mapped item, then bake them to new maps on the Victoria 4-mapped figure. You could then save those out and use them on Victoria 4 in Poser. Unfortunately this isn't a job others could do for you as it would involve distributing derivative mesh and/or derivative textures in a way not covered by the Daz (for models, and textures from Daz) or (for textures) other store licenses.