The best way to handle this would be to create a simple userform with a label, which can be configured to display any font available at any practical size and use Paul's macros to write the result to the label caption instead of to the message box.
Import the userform from the attached zip file into the same template as the macro code and call it by changing both lines from
to
Code:
With frmCalculator
.Caption = "Total"
.lblResult.Caption = iTotal
.lblResult.Font.Size = 24
.Show
End With