Set the stream position.
Source position: types.pp line 507
| function IStream.Seek( | 
| dlibMove: Largeint; | 
| dwOrigin: DWORD; | 
| out libNewPosition: LargeUint | 
| ):HRESULT; | 
Seek sets the stream position at dlibMove bytes from dwOrigin (one of the SEEK_* constants) and returns the new absolute position in libNewPosition. The function returns zero on success, or an error code.
On error, a nonzero exit code is returned.