Problems handling click event on dynamically created buttons

I've created a project where I originally have two buttons (button_a and button_b) that every time they are pressed generate a new button (button_c1, button_c2, button_c3. when button_a is pressed and button_d1, button_d2, button_d3. when button_b is pressed).
The problem I have is that it seems that as the buttons aren't created in Page_Load, the AddHandler I use doesn't work. How should I handle the click event of this new dynamically created buttons?


Here's how my code looks:

Public Partial Class new_buttons
    Inherits System.Web.UI.Page
 
    Protected Sub button_a_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles button_a.Click
        Dim button_c_num As Integer += Session("button_c_count")
        Gen_button_c(button_c_num)
 &nb ...