check if IsNumeric using Me.Controls() - excel

Question

I have a userform with dozens of text boxes where the user should input only numbers from 1 to 6. When the form is completed the user clicks Save and the numbers are added to an Excel table.
As the text boxes are quite a lot I used the following code to read their value:
' Text boxes name are: txt_a01, txt_a02, txt_a03...
For i = 1 To 5
ws.Cells(iRow, i).Value = Me.Controls("txt_a0" & i).Value
Next
' Here text boxes name are: txt_b01, txt_b02, txt_b03...
For i = 6 To 10
ws.Cells(iRow, i).Value = Me.Controls("txt_b0" & i - 5).Value
Next
etc.
rather than write dozens of times:
ws.Cells(iRow, 1).Value = Me.txt_a01.Value
ws.Cells(iRow, 2).Value = Me.txt_a02.Value
ws.Cells(iRow, 3).Value = Me.txt_a03.Value
ws.Cells(iRow, 4).Value = Me.txt_a04.Value
ws.Cells(iRow, 5).Value = Me.txt_a05.Value
Now I would like to check - during input - if the user has really added a number and if its between 1 and 6. Normally I would do it like this:
Private Sub txt_a01_AfterUpdate()
If Not IsNumeric(txt_a01.Value) Then
MsgBox ("Only numbers accepted")
End If
End Sub
But as I use a FOR - LOOP and Me.Controls() to read the text box values I don't understand how to write down the _AfterUpdate Sub.

Answer 1

You could attach dynamically an event handler on form load or you could create a custom control with an event.
Personally I prefer use custom control and KeyPressEventHandler to refuse all not allowed chars.
You may create a class to handle the event :
Private WithEvents m_oTextBox as TextBox
Public Property Set TextBox(ByVal oTextBox as TextBox)
Set m_oTextBox = oTextBox
End Property
Private Sub m_oTextBox_Change()
' Do something
End Sub
then, for each control:
Dim myEventHandler As TextBoxEventHandler
Set myEventHandler = New TextBoxEventHandler
Set myEventHandler.TextBox = oControl
m_oCollectionOfEventHandlers.Add myEventHandler