Attached Link: http://www.castironflamingo.com/tutorial/grouper/index.html

You need Grouper from the attached link to make your life easier. Then you don't need to worry about that dialogue box. Export your obj file. Open it in Grouper. Click "Scan". Then associate all the bits that use the same transparency map; for example, Vairesh's Total Hair has three transparency maps for scalp, fringe and the rest, although there are about six meshes in all, so you would group four, one and one. If you study the render materials screen in Poser you can find which materials in the hair use which transparency map. You still have to apply the transmaps by hand in Bryce, but at least you can now find more easily the right parts. In the end you can have a very nice result.