#include <Constants.au3>
#include <WinAPI.au3>
#include <WinAPIFiles.au3>

Global Const $tagIOSTATUSBLOCK = "dword Status;ptr Information"
Global Const $tagFILEINTERNALINFORMATION = "int IndexNumber;"

MsgBox(0,'',_GetIndexNumber(@UserProfileDir & '\NTUSER.DAT'))

Func _GetIndexNumber($path)
   Local $sISB = DllStructCreate($tagIOSTATUSBLOCK)
   Local $buffer = DllStructCreate("byte[16384]")
   Local $hFile = _WinAPI_CreateFileEx('\\?\' & $path, $OPEN_EXISTING, 0, BitOR($FILE_SHARE_READ, $FILE_SHARE_WRITE), BitOR($FILE_FLAG_BACKUP_SEMANTICS, $FILE_FLAG_OPEN_REPARSE_POINT))
   If @error Then Return SetError(1, @extended, '')
   Local $aRet = DllCall('ntdll.dll', 'long', 'ZwQueryInformationFile', 'handle', $hFile, 'struct*', $sISB, 'struct*', $buffer, 'ulong', 16384, 'uint', 6)
   If @error Then Return SetError(2, @extended, '')
   If $aRet[0] Then Return SetError(3, $aRet[0], '')
   Local $pFSO = DllStructGetPtr($buffer)
   Local $sFSO = DllStructCreate($tagFILEINTERNALINFORMATION, $pFSO)
   Local $IndexNumber = DllStructGetData($sFSO, "IndexNumber")
   _WinAPI_CloseHandle($hFile)
   Return $IndexNumber
EndFunc