Ok, first you export your object as a wavefront.obj into a new folder. Then come out of Poser and open Grouper. There are five tabs along the top. Click on the first one "Files". You browse to where you placed the .obj, click and thats the source file. The destination file field is best left alone as it will give you the same directory as the source. Now click on "Groups". Along the right side are more tabs. Click on scan. This will get all the materials used in your Obj. Then under map click save. Now go to the fourth tab, "Convert and Repair". In the first window browse to where you keep your Poser textures and click "Include". This can take some time but you only have to do it once Now click "Package" and when thats done,click "Convert"

What all this does is get a list of materials used and then makes a folder with the addresses of those materials.
In practice you import the .Obj and when it says a material cannot be found, it should open up the same folder window in which you saved the obj. Here you will also find a folder of the maps.
It sounds complicated but really it`s the work of seconds once you get used to it.

Hope this makes sense and is of help.