running a private sub macro

hello everyone, i have been searching the internet for an answer for my problem... i have a macro that shows a user form and asks the user to fill up certain fields. there is one point wherein i want to automatically get the total of all numeric data entered in assigned textboxes. I tried running the application through calling another macro everytime a textbox gets updated. but there is always a problem... my sample code is shown below... i hope someone can help me with this one.

Private Sub TextBox9_afterupdate()
    Dim num(1 To 9) As Currency
        num(1) = TextBox9.Value
        TextBox13.Value = num(1)
    TextBox9.Value = Format(TextBox9.Value, "#,###.#0")
    TextBox13.Value = Format(TextBox13.Value, "#,###.#0")
    Application.run "'sample.xls'!runtotal"
End Sub

everytime i run the macro, i get runtime error '1004'....