internal static extern int StgCreatePropSetStg(UCOMIStorage storage, int reserverd, out IPropertySetStorage propSetStg);
internal static extern int StgCreateStorageEx([MarshalAs(UnmanagedType.LPWStr)] string wcsName, int grfMode, int stgfmt, int grfAttr, IntPtr StgOptions, IntPtr reserved2, ref Guid refiid, out UCOMIStorage storage);
internal static extern int StgOpenStorage([MarshalAs(UnmanagedType.LPWStr)] string wcsName, IntPtr stgPriority, int grfMode, IntPtr snbExclude, int reserved, out UCOMIStorage storage);
internal static extern int StgCreateDocfileOnILockBytes(UCOMILockBytes plkbyt, int grfMode, int reserved, out UCOMIStorage storage);
internal static extern int StgCreateDocfile([MarshalAs(UnmanagedType.LPWStr)] string wcsName, int grfMode, int reserved, out UCOMIStorage storage);