Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As Long, ByVal lpWindowName As Long) As Long
Private Declare Function GetParent Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function SetParent Lib "user32" (ByVal hWndChild As Long, ByVal hWndNewParent As Long) As Long
Private Declare Function GetWindowThreadProcessId Lib "user32" (ByVal hwnd As Long, lpdwProcessId As Long) As Long
Private Declare Function GetWindow Lib "user32" (ByVal hwnd As Long, ByVal wCmd As Long) As Long
Private Declare Function LockWindowUpdate Lib "user32" (ByVal hwndLock As Long) As Long
Private Declare Function GetDesktopWindow Lib "user32" () As Long
Private Declare Function DestroyWindow Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function TerminateProcess Lib "kernel32" (ByVal hProcess As Long, ByVal uExitCode As Long) As Long
Private Declare Function GetCurrentProcess Lib "kernel32" () As Long
Private Declare Function Putfocus Lib "user32" Alias "SetFocus" (ByVal hwnd As Long) As Long
Const GW_HWNDNEXT = 2
Dim mWnd As Long
Function InstanceToWnd(ByVal target_pid As Long) As Long
    Dim test_hwnd As Long, test_pid As Long, test_thread_id As Long
    'Find the first window
    test_hwnd = FindWindow(ByVal 0&, ByVal 0&)
    Do While test_hwnd <> 0
        'Check if the window isn't a child
        If GetParent(test_hwnd) = 0 Then
            'Get the window's thread
            test_thread_id = GetWindowThreadProcessId(test_hwnd, test_pid)
            If test_pid = target_pid Then
                InstanceToWnd = test_hwnd
                Exit Do
            End If
        End If
        'retrieve the next window
        test_hwnd = GetWindow(test_hwnd, GW_HWNDNEXT)
    Loop
End Function
Private Sub Form_Load()
    'KPD-Team 1999
    'URL: http://www.allapi.net/
    'E-Mail: KPDTeam@Allapi.net
    Dim Pid As Long
    'Lock the window update
    LockWindowUpdate GetDesktopWindow
    'Execute notepad.Exe
    Pid = Shell("c:\windows\notepad.exe", vbNormalFocus)
    If Pid = 0 Then MsgBox "Error starting the app"
    'retrieve the handle of the window
    mWnd = InstanceToWnd(Pid)
    'Set the notepad's parent
    SetParent mWnd, Me.hwnd
    'Put the focus on notepad
    Putfocus mWnd
    'Unlock windowupdate
    LockWindowUpdate False
End Sub
Private Sub Form_Unload(Cancel As Integer)
    'Unload notepad
    DestroyWindow mWnd
    'End this program
    TerminateProcess GetCurrentProcess, 0
End Sub