Sub convertToNonNumbersAndClean()
    Application.Calculation = xlCalculationManual
    For Each cell In Selection.SpecialCells(xlCellTypeConstants)
        x = CStr(cell.Value)
        cell.ClearContents
        cell.NumberFormat = "@"
        cell.Value = x
        If Left(x, 1) = "0" Then
            x = Mid(x, 2, Len(x) - 1)
        End If
    Next
    Application.Calculation = xlCalculationAutomatic
End Sub