Off the top of my head:

On Error Resume Next
Debug.Print Sheets(1).Columns(colTxt).Column
If Err.Number = 13 Then
' Not a valid reference.
Debug.Print "Error"
Else
' Valid Reference.
Debug.Print "OK"
End If
On Error GoTo 0



--

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+-- JDMils
|

"Geoff" wrote in message
...
Hi
I have a textbox on a form and want the user to input a column header.
How
can I prevent the user inputting a value greater than 'IV' ?

Inputting 'K' yields 11 in the test msgbox
Inputting 'KK' gives a 'Type Mismatch' error.

Private Sub txt1_Change()

txt1.Text = UCase(txt1.Text)

''' for syntax testing only
MsgBox Sheets(1).Columns(txt1.Text).Column

If Not Sheets(1).Columns(txt1.Text).Column 256 Then
''' do something
Else
MsgBox "No such column"
End If

End Sub

T.I.A.

Geoff