[DllImport("shlwapi.dll", CharSet = CharSet.Unicode)]
public static extern bool PathRelativePathTo(
StringBuilder pszPath,
[MarshalAs(UnmanagedType.LPWStr)] string pszFrom,
DWORD dwAttrFrom,
[MarshalAs(UnmanagedType.LPWStr)] string pszTo,
DWORD dwAttrTo
);