ExcelWorkbooks.au3

Func ExcelWorkbooks()
  ; Error handler, automatic cleanup at end of function
  Local $oError = ObjEvent("AutoIt.Error", "__Excel_COMErrFunc")
  #forceref $oError
  Local $oWorkbook, $iCount = 0, $sCLSID_Workbook = "{00020819-0000-0000-C000-000000000046}" ; Microsoft.Office.Interop.Excel.WorkbookClass
  Dim $sBooks[100]
  While True
    $oWorkbook = ObjGet("", $sCLSID_Workbook, $iCount + 1)
    If @error Then
       ReDim $sBooks[$iCount]
       Return $sBooks
      EndIf
    $sBooks[$iCount] = $oWorkbook.FullName
    $iCount += 1
  WEnd
EndFunc   ;==>ExcelWorkbooks