Changes the seek pointer to a new location relative to the beginning of the stream, to the end of the stream, or to the current seek pointer.
dlibMove Displacement to add to dwOrigin. dwOrigin Specifies the origin of the seek. The origin can be the beginning of the file, the current seek pointer, or the end of the file. plibNewPosition On successful return, contains the offset of the seek pointer from the beginning of the stream.
For more information, please see the existing documentation for IStream::Seek in the MSDN library.