A very valuable sub-class source code!

' Create a new ActiveX DLL project, name Smartsubclasslib
' The following code is placed in the standard module, the module name Msmartsubclass
' ----------------------------------------------------
' Module Msmartsubclass
'
' Version ... 1.0
' Date ... April 2001
'
' Copyright (C) 2001 Andr anecdote Pons (andres@vbsmart.com)
' ----------------------------------------------------
' API declarations:
Option Explicit
Public Const Ssc_oldproc = "Ssc_oldproc"
Public Const ssc_objaddr = "Ssc_objaddr"
Private Declare Function getprop Lib "user32" Alias "Getpropa" (_
ByVal HWnd as Long, _
ByVal lpstring as String) as Long
Private Declare Sub copymemory Lib "kernel32" Alias "RtlMoveMemory" (_
Destination as Any, _
Source as Any, _
ByVal Length as Long)
'
' Function Startsubclasswindowproc ()
'
' This is the ' WindowProc ' receives messages
' For all subclassed windows.
' The aim ' 's ' is ' to just collect the message
' and deliver it to the right Smartsubclass instance.
'
Public Function Smartsubclasswindowproc (_
ByVal HWnd as Long, _
ByVal umsg as Long, _
ByVal WParam as Long, _
ByVal LParam as Long) as long
Dim Lret as Long
Dim Osmartsubclass as Smartsubclass
"Get" memory address of the class instance ...
Lret = Getprop (hWnd, SSC_OBJADDR)

If Lret <> 0 Then
' Osmartsubclass ' to the class instance
' Without incrementing the class reference counter ...
CopyMemory Osmartsubclass, Lret, 4
' Send the message to the class instance ...
Smartsubclasswindowproc = Osmartsubclass.windowproc (HWnd, _
Umsg, WParam, LParam)