Then I guess you should use the shade format, but I don't know it,  apparently, it imports the geometry and the textures. If you have transparency problems ( like leaves appearing as squares in Vue), here's what you should do:

Create an alpha plane, and in the colour image, load the bitmap used by Xfrog for the leaf. If the bitmap has embedded transparency, Vue will recognize it and offer to load the transmap in the transparency channel. say yes!

If not, load the transmap that correspond to the color bitmap in the alpha image of the alpha plane. You may need to invert the transmap to get the alpha plane right ( click the little black dot next to the alpha picture of the alpha plane, upper right corner)

When this is done, copy/paste the alpha plane material onto your leaf material.