Поместить чужое окно в окне своего приложения - Visual Basic .NET

Public Class Form1
    Declare Auto Function SetParent Lib "user32.dll" (ByVal hWndChild As IntPtr, ByVal hWndNewParent As IntPtr) As Integer
    Declare Auto Function SendMessage Lib "user32.dll" (ByVal hWnd As IntPtr, ByVal Msg As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As Integer
    Private Const WM_SYSCOMMAND As Integer = 274
    Private Const SC_MAXIMIZE As Integer = 61488
    Dim proc As Process
  
  Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        Dim proc As Process
        proc = Process.Start("notepad")
        proc.WaitForInputIdle()
        SetParent(proc.MainWindowHandle, Me.Handle)
        SendMessage(proc.MainWindowHandle, WM_SYSCOMMAND, SC_MAXIMIZE, 0)
    End Sub
End Class