spero di non sbagliare
questo e' il codice da inserire nel form

codice:
Option Explicit

Private Sub RitagliaForm(ByVal Incremento As Single)
Dim pts(1 To 57)    As PosizioneCursore
Dim rgn             As Long
Dim OldRgn          As Long
Dim str             As String
Dim str2            As String
Dim k               As Integer
Dim J               As Integer
Dim Sch             As Variant
Dim Sch2            As Variant

    str = "*327*296*254*237*185*182*123*134*71*96*32*70*8*56*0*56*" & _
          "8*70*32*96*71*134*123*182*185*237*254*296*327*358*400*" & _
          "417*469*472*531*520*583*558*622*584*646*598*654*598*646*" & _
          "584*622*558*583*520*531*472*469*417*400*358*327*"
    str2 = "*0*29*5*35*17*49*36*68*62*92*93*119*128*149*164*179*200*" & _
           "209*235*236*266*260*292*279*311*293*323*299*328*299*323*" & _
           "293*311*279*292*260*266*236*235*209*200*179*164*149*128*" & _
           "119*93*92*62*68*36*49*17*35*5*29*0*"
    Sch = Split(str, "*")
    Sch2 = Split(str2, "*")
    For k = 1 To 57
        pts(k).Ascissa = CLng(Sch(k))
        pts(k).Ordinata = CLng(Sch2(k))
    Next k
    Me.Cls
    If Incremento > 1 Then Incremento = 1
    For J = 1 To 57
        pts(J).Ascissa = pts(J).Ascissa * Incremento + _
                        (Me.Width / 2 / Screen.TwipsPerPixelX) - _
                        (Me.Width / 2 / Screen.TwipsPerPixelX * Incremento)
        pts(J).Ordinata = pts(J).Ordinata * Incremento + _
                          (Me.Height / 2 / Screen.TwipsPerPixelY) - _
                          (Me.Height / 2 / Screen.TwipsPerPixelY * Incremento)
    Next J
    rgn = CreatePolygonRgn(pts(1), 57, 2)
    OldRgn = SetWindowRgn(hwnd, rgn, True)
    Me.Refresh
End Sub

Private Sub Form_Resize()
Dim Start As Double
Dim Temp As Single
Dim Delay As Single
            
    Me.Left = Screen.Width * (100 - 98) / 200
    Me.Top = Screen.Height * (100 - 98) / 200
    Me.Width = Screen.Width * 98 / 100
    Me.Height = Screen.Height * 98 / 100 - 500
    
    Me.BackColor = 255
    Delay = 0.01
    For Temp = 0.1 To 1.1 Step 0.01
        Call RitagliaForm(Temp)
        Start = Timer
        Do While Timer < Start + 0.01
            DoEvents
        Loop
    Next Temp
End Sub

e questo quello da inserire nel modulo

codice:
Public Type PosizioneCursore
    Ascissa                     As Long
    Ordinata                    As Long
End Type

Declare Function CreatePolygonRgn _
                    Lib "GDI32" ( _
                        lpPoint As PosizioneCursore, _
                        ByVal nCount As Long, _
                        ByVal nPolyFillMode As Long) _
                 As Long

Declare Function SetWindowRgn _
                    Lib "user32" ( _
                        ByVal hwnd As Long, _
                        ByVal hRgn As Long, _
                        ByVal bRedraw As Boolean) _
                 As Long