Add two command buttons (Command1 , Command2) and add the following code :

VB Code:
  1. Private Declare Function SwapMouseButton& Lib "user32" (ByVal bSwap As Long)

  2. Private Declare Function SystemParametersInfo Lib "user32" Alias "SystemParametersInfoA" (ByVal uAction As Long, ByVal uParam As Long, ByVal lpvParam As Any, ByVal fuWinIni As Long) As Long

  3.  
  4. Private Sub Command1_Click()

  5.  'swap Left and Right mouse buttons

  6.  SwapMouseButton (True)

  7. End Sub

  8.  
  9. Private Sub Command2_Click()

  10.  'set mouse buttons back to normal

  11.  SwapMouseButton (False)

  12. End Sub

  13.  
  14. Private Sub Form_Load()

  15.  Command1.Caption = "swap"

  16.  Command2.Caption = "unswap"

  17. End Sub