Private Declare Function SetLayeredWindowAttributes Lib "user32.dll" (ByVal _
  hwnd As Long, ByVal crKey As Long, ByVal bAlpha As Byte, ByVal dwFlags As _
  Long) As Boolean
Private Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" ( _
ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Private Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" ( _
ByVal hwnd As Long, ByVal nIndex As Long) As Long
 
Const LWA_ALPHA = 2
Const GWL_EXSTYLE = (-20)
Const WS_EX_LAYERED = &H80000
 
Private Sub Form_Load()
SetWindowLong hwnd, GWL_EXSTYLE, GetWindowLong(hwnd, GWL_EXSTYLE) Or _
  WS_EX_LAYERED
    SetLayeredWindowAttributes hwnd, 0, 128, LWA_ALPHA
End Sub