Why wouldn't you be able to use the "Prepar3D v2" export, and configure it to your P3Dv3 folder?   Step 1) Select "Pepar3D v2"  

Please login to display this image.

  Step 2) Click on "Browse" and select your "Prepar3D v2 Files" folder below your "Documents" folder  

Please login to display this image.