The IDirectSound3DBuffer::SetPosition method sets the sound buffer's current position, in distance units. By default, distance units are meters, but the units can be changed by using the IDirectSound3DListener::SetDistanceFactor method.
HRESULT SetPosition(
  D3DVALUE x,    
  D3DVALUE y,    
  D3DVALUE z,    
  DWORD dwApply  
);
 If the method succeeds, the return value is DS_OK.
If the method fails, the return value may be DSERR_INVALIDPARAM.
  Windows NT/2000: Requires Windows 2000.
  Windows 95/98: Requires Windows 95 or later. Available as a redistributable for Windows 95.
  Header: Declared in dsound.h.
  Import Library: Use dsound.lib.