Imports System.Runtime.InteropServices
Public Class Form1
    <StructLayout(LayoutKind.Sequential)>
    Public Structure Margins
        Public cxleftwidth As Integer
        Public cxrightwidth As Integer
        Public cytopheight As Integer
        Public cybottomheight As Integer
    End Structure
    <DllImport("dwmapi.dll")> Public Shared Function DwmExtendFrameIntoClientArea(ByVal hWnd As IntPtr, ByRef pMarinset As Margins) As Integer
    End Function
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim margins As Margins = New Margins
        margins.cxleftwidth = 2
        margins.cxrightwidth = 2
        margins.cytopheight = 23
        margins.cyBottomHeight = 2
        Dim hwnd As IntPtr = Handle
        Dim result As Integer = DwmExtendFrameIntoClientArea(hwnd, margins)
    End Sub
End Class