Option Explicit
Private Declare SetLayeredWindowAttributes Lib "user32" (ByVal hwnd As Long, ByVal crKey As Long, ByVal bAlpha As Byte, ByVal dwFlags As Long) As Long
Private Declare GetWindowLong Lib "user32" Alias "GetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long) As Long
Private Declare SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Const WS_EX_LAYERED = &H80000
Const GWL_EXSTYLE = (-20)
Const LWA_ALPHA = &H2
Const LWA_COLORKEY = &H1
Private Sub Form_Load()
    Dim sty As Long
    sty = GetWindowLong(Me.hwnd, GWL_EXSTYLE)
    sty = sty Or WS_EX_LAYERED
    SetWindowLong Me.hwnd, GWL_EXSTYLE, sty
    SetLayeredWindowAttributes Me.hwnd, 0, 100, LWA_ALPHA
End Sub