I don't know what is wrong in this sub?? It gives me syntax error(Ignore the asterisks)

Sub InsertIFERROR()
*** Dim R As Range
*** For Each R In Selection.SpecialCells(xlCellTypeFormulas)
******* R.Formula = "=IFERROR(" & Mid(R.Formula, 2) & ",""0"")"
*** Next R
End Sub