Mudbox :: How To Bring Image Into Paint Layer

It try bring an image into paint layer. I found that there is this function:

PaintLayerImporter() and it takes 4 parameters. They are:

1) const QString &sFileName, ///< Name of the file to import
2) int iFileTypeIndex, < Index of the type of the file in the array returned by SupportedExtensions

3) Mesh *pMesh, ///< Mesh which contains the paint layer
4) TexturePool *pTarget ///< Destination of the import operation

But I'm not able to get this function to work. Any small example how to use it.

I think that main problem for me is that I don't know exactly what 2) parameter means(int iFileTypeIndex). It says that you get that from SupportedExtensions but When I look at it:

virtual QVector<FileExtension> SupportedExtensions( void );

It surely dosen't look int.