ExportDirectX(obj, filename$)
obj: object to export.
filename$: file to export.
Returns 1 if succeeded, 0 if file exist or filename$ is not a DirectX file.

This only works on objects with indices. This means that memblock objects won't work. So do file formats that don't support indices.
The example can load DirectX and 3D studio models, and exports them using the function to a new file.
(Make sure the file doesn't exist)

The dialog code is from JessT.

I have experienced that DBO files can't be exported with this functions.