When you save the file in poser... save it as a .png file. Or alternatively, you can save it as a .tiff file and then in the graphic program apply a new mask layer and it will remove the background. Don't forget to delete the mask later once done. Otherwise if you add colour to that layer, it will be as a mask instead of a true layer.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi