Further to my question: Calling private functions using combobox-Collection of common programming errors

You will need to use reflection to achieve this. Reflection is the process by which a computer program can observe and modify its own structure and behavior at runtime

Add Imports System.Reflection before your class definition and use this code in you ComboBox1_SelectedIndexChanged method

Dim vrTextNow As String = ComboBox1.Text
        Dim method As MethodInfo
        method = Me.GetType().GetMethod(vrTextNow, BindingFlags.NonPublic Or BindingFlags.Instance)
        method.Invoke(Me, Nothing)