Also I don't use those commands I certainly would also like to know how to do it.
I had the privilege to meet one of the XFCE gurus, Sproggy, in the IRC channels and asked. Here is what he came up with:
mv %F $(zenity --file-selection --directory) <~~~ move file/directory
cp %F $(zenity --file-selection --directory) <~~~ copy file/directory
move/copy file appearance conditions tab put a tick in all
quite nifty. Hope this helps.