You gave a simple solution to setting the new Blender and Yafray export builds Yafray program path. In the drop down menu I added the link to the Yafray rendering software in the "YFexport:" setting.
I set the "YFexport:" to g:\YafRay\- where Yafray is installed. It works!
I hope that this helps other Windows users to test out the new Blender software with Yafray Exporting.