If you open the OBJ file or the MTL file in a text editor, you can manually change the path locations of your textures.  However, this should be something you can adjust on the export end.  I don't have Poser, so I don't know the export settings capabilities, but there should be an area in there where you can specify a relative or absolute location for your textures or allow you to enable the option to copy textures to the export location folder with your OBJ. 

______________________________________

My Store
My Free Models
My Video Tutorials
My CG Animations
Instagram: @luxxeon3d
Facebook: https://www.facebook.com/luxxeon