iOS Question [SOLVED] Regex / Textfield / How to handle also first character?

Private Sub txtNumberNumber_TextChanged (Old As String, New As String)
    Dim update As Boolean
    
    Try
        Dim text As String = Regex.Replace("\D", New, "")
        If New <> text Then
            update = True
        End If
    Catch
        Log(LastException.Message)
    End Try
    
    If text.Length > 3 Then
         text.SubString2(0,3)
         update = True
    End If
    
    If update Then
        txtNumberNumber.Text = text
        txtNumberNumber.SetSelection(text.Length,text.Length)
    End If
    
End Sub