The SSUBTMR.DLL is a modified version of HardCore Visual Basic's SUBTIMER.DLL, with a few revisions and bug patches by VB Accelerator. To download it, click here. To use it, do the following:

1) Add the following code to the general declarations section of the form you want to subclass

Implements ISubclass
Private m_emr As EMsgResponse
Private bSubclassing As Boolean

2) Also add the declarations of any messages you want to include. For example:

Public Const WM_SYSCOMMAND = &H112

3) For each message you want to subclass, you need to add a call to AttachMessage and DetachMessage. An example is given, and it uses the following syntax:

AttachMessage Form with the Implements statement, Form.hwnd you want to subclass's property, Message you want to subclass. 

For example:

AttachMessage Me, hwnd, WM_OTHERWINDOWDESTROYED

So, add the following procedures.

Public Sub pAttachMessages()
    m_emr = emrPreprocess
    '// delete this example, and add your own
    AttachMessage Me, hwnd, WM_OTHERWINDOWDESTROYED
    bSubclassing = True
End Sub
Private Sub pDetachMessages()
   If (bSubclassing) Then
        '// delete this example, and add your own
        DetachMessage Me, hwnd, WM_OTHERWINDOWDESTROYED
        bSubclassing = False
   End If
End Sub

4) Then, add the following code:

Private Property Let ISubclass_MsgResponse(ByVal RHS As SSubTimer.EMsgResponse)
    '// this proc is not really needed, but you still need to add it!
End Property

Private Property Get ISubclass_MsgResponse() As SSubTimer.EMsgResponse
    '// Tell the subclasser what to do for this message (here we do all processing):
    ISubclass_MsgResponse = emrPreprocess
End Property

Private Function ISubclass_WindowProc(ByVal hwnd As Long, ByVal iMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
    Select Case iMsg
    '// add Case statements for each message you wanted subclassed:
    Case WM_MESSAGE1
        '// enter what you want to do when WM_MESSAGE1 occurs
    Case WM_MESSAGE2
        '// enter what you want to do when WM_MESSAGE2 occurs ...
    End Select
End Function

There is also an example available for download from VB Accelerator: Download the SSubTmr project code (no DLL) (9kb)