'Описания см. по ссылке выше
Private Sub CreateWindowArray( _
   SourceArray() As Double, WindowArray() As Double, saWindow As SAFEARRAY1VT, _
   ByVal WindowPos As Long, ByVal WindowLBound As Long, _
   ByVal WindowLength As Long)
 Dim ppsaWindow As Long
 
 saWindow.vtType = VarType(SourceArray(LBound(SourceArray)))
 With saWindow.sa
    .cDims =  1 
    .fFeatures = FADF_HAVEVARTYPE Or FADF_FIXEDSIZE
    .cbElements = LenB(SourceArray(LBound(SourceArray)))
    '.cLocks = 1
    .pvData = VarPtr(SourceArray(WindowPos))
    With .rgsabound( 0 )
       .lLbound = WindowLBound
       .cElements = WindowLength
    End With
 End With
    
 ppsaWindow = ArrPtr(WindowArray())
 CopyMemory ByVal ppsaWindow, VarPtr(saWindow.sa), LenB(ppsaWindow)
End Sub

Private Sub ClearWindowArray(WindowArray() As Double)
 Dim ppsaWindow As Long
 ppsaWindow = ArrPtr(WindowArray())
 CopyMemory ByVal ppsaWindow,  0 &, LenB(ppsaWindow)
End Sub

Private Sub MoveWindowArray( _
   SourceArray() As Double, saWindow As SAFEARRAY1VT, _
   ByVal WindowPos As Long)
 saWindow.sa.pvData = VarPtr(SourceArray(WindowPos))
End Sub

Private Sub Test2()
 Dim X( 100 ) As Double
 Dim Y( 100 ) As Double
 Dim x1() As Double
 Dim y1() As Double
 Dim i As Long
 Dim sax1 As SAFEARRAY1VT
 Dim say1 As SAFEARRAY1VT
 
 'Заполнение больших массивов
 For i = LBound(X) To UBound(X)
    X(i) = i
 Next i
 For i = LBound(Y) To UBound(Y)
    Y(i) =  1  + i /  1000 
 Next i
 
 'Наложение "окон"
 CreateWindowArray X(), x1(), sax1,  40 ,  0 ,  21 
 CreateWindowArray Y(), y1(), say1,  32 ,  1 ,  10 
 
 'Использование "окон"
 For i = LBound(x1) To UBound(x1)
    Debug.Print i, x1(i)
 Next i
 For i = LBound(y1) To UBound(y1)
    Debug.Print i, Format$(y1(i), "0.000")
 Next i
 
 'Перемещение имеющегося "окна"
 MoveWindowArray X(), sax1,  13 
 
 'Использование перемещённого "окна"
 For i = LBound(x1) To UBound(x1)
    Debug.Print i, x1(i)
 Next i
 
 'Уничтожение "окон"
 ClearWindowArray x1()
 ClearWindowArray y1()
End Sub

Private Sub Command2_Click()
 Test2
End Sub