I assume you don't mean image? CR2s can have embedded geometry; this type would need no external OBJ. If you look in the CR2 with a text editor that can handle large files, you normally see a line somewhere near the top which starts "figureResFile" and ends with the name of a .obj file. If you don't have such a line, you have embedded geometry and your item should work as is. If you do, then you need the obj file that's referred to. If the rsr file you have has the same root as the cr2, it will be the thumbnail; if it has the same root as the figureResFile obj, it's the geometry. I think Poser will accept a geometry rsr without the corresponding obj. If not, there's a utility for getting it back. However, if your CR2 calls for external geometry, and your rsr file isn't it, you're stuck. You would need to contact the item's maker and ask for a replacement obj.