This is how you intercepts msgs in .NET application . If it doesn't work for you then I'm sorry it's my first shot with CFW .

VB Code:
  1. 'Declare message const
  2.  
  3. Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)
  4.         Select Case m.Msg
  5.  
  6.             Case WM_VSCROLL
  7.                 'do this
  8.  
  9.         End Select
  10.  
  11.         MyBase.WndProc(m)
  12.  
  13.     End Sub