How to handle an button click even from a .dll - vb.net

Question

Could someone please guide me as to how I would get this actually working? Currently it gives me errors about WithEvents - although simplified it shows the form - but I have no clue what that actually means. It's an toolbox I'm making just to allow the user to better interact with some of my other code.
All I need is the form visuals/guts to be custom, but then the code to be done within my application (which doesn't have visual editing capabilities).
Is this a case where I need to use interfacing/partial classes/inheritance, or can this easily be accomplished with just some minor tweaking to what I have?
(Form created in visual studio form designer and then changed to a class library. Application code written in Autodesk Inventor "rule" environment)
Thanks!
Application code:
AddReference "C:\Users\Documents\Visual Studio 2013\Projects\WindowsApplication1\WindowsApplication1\bin\Release\SectionSymToolBox.dll"
Imports System.Windows.Forms
Public Class SectionSymRule
'Public dlg As New System.Windows.Forms.For
Public Shared ToolBox As New SectionSymToolBox.SectionSymToolBox
Dim WithEvents EClass As New EventClass
Sub Main()
ToolBox.Show()
End Sub
End Class
Form code:
Public Class SectionSymToolBox
Private Sub Main()
End Sub
Public Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
'Swap Symbols
End Sub
Public Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
'Flip Symbol
End Sub
Public Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
'Flip Text
End Sub
Public Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click
'<
End Sub
Public Sub Button5_Click(sender As Object, e As EventArgs) Handles Button5.Click
'>
End Sub
End Class

Answer 1

Is this what you are looking for?
AddHandler ToolBox.Button1.Click, AddressOf HandlerMethodHere
Where HandlerMethod is a method that has the same signature as Button1.Click so for example:
Private Sub HandleButton1Click(sender As Object, e As EventArgs)
'Code here
End Sub
Obviously, replace Button1 with the name of the button.