Cells( 1 , 1 ).FormulaR1C1 =  "=(SUM(RC2:RC[-1 ]))/R1C[- 1 ]"

Private Sub ExcelOutput()
  Dim ExcelSheet As Object
  Set ExcelSheet = CreateObject( "Excel.Application" )
' Make Excel visible through the Application object.'
  ExcelSheet.Application.Visible = True
  
'  Each new Workbook will contain only one Sheet'
  Temp = ExcelSheet.Application.SheetsInNewWorkbook
  ExcelSheet.Application.SheetsInNewWorkbook =  1 
  ExcelSheet.Application.Workbooks.Add
  ExcelSheet.Application.SheetsInNewWorkbook = Temp
  
'  Get Workbook and sheet name'
  BookName = ExcelSheet.Application.ActiveWorkbook.NAME
  SheetName = ExcelSheet.Application.ActiveWorkbook.ActiveSheet.NAME

  ExcelSheet.Application.Workbooks(BookName).Sheets(SheetName).Cells( 1 ,  1 ).Value =  "This is column A, row 1 "
  ExcelSheet.Application.Workbooks(BookName).Sheets(SheetName).Cells( 2 ,  2 ).Value =  "This is column B, row 2 "
  ExcelSheet.Application.Workbooks(BookName).Sheets(SheetName).Cells( 3 ,  3 ).FormulaR1C1 =  "=LEFT(R2C2)" 

'  Make Excel do not alert on close unsaved document'
  Temp = ExcelSheet.Application.DisplayAlerts
  ExcelSheet.Application.DisplayAlerts = False
  ExcelSheet.Application.Quit
  ExcelSheet.Application.DisplayAlerts = Temp

' Release the object variable.'
  Set ExcelSheet = Nothing
End Sub