MotokoKusanagi Kutanaga

Directly from Poser, no. If you want something from Poser to use in SL you have to export it into a 3D modeling program that supports creating sculpties, break down the Poser mesh or re-create it into smaller meshes that can be used as a sculpt base, re-make any textures to fit the smaller meshes and then export the lot as a series of sculpt maps and textures. Until LL actually comes out with Mesh Import, which will be no time soon, that's the way it has to be.