Retrieves the current selection from a list box.
It assumes that the list box has been filled by the DlgDirList member function and that the selection is a drive letter, a file, or a directory name.
The DlgDirSelect member function copies the selection to the buffer given by lpString. If there is no selection, lpString does not change.
It does not allow more than one filename to be returned from a list box. The list box must not be a multiple-selection list box.