'To display a timed Msgbox use the MsgboxOKDrop routine given below.
'By Andrew Baker

Option Explicit

'API calls for Msgbox2. Must be placed in a standard module
Declare PtrSafe Function SetTimer Lib "user32" (ByVal Hwnd As Long, ByVal nIDEvent As Long, ByVal uElapse As Long, ByVal lpTimerFunc As Long) As Long
Declare PtrSafe Function KillTimer Lib "user32" (ByVal Hwnd As Long, ByVal nIDEvent As Long) As Long
Declare PtrSafe Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long
Declare PtrSafe Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal Hwnd As Long, ByVal wMsg As Long, ByVal wParam As Integer, ByVal lParam As Any) As Long
Private zsMessageTitle As String, lTimerId As Long

'Purpose     :  Stops the timer routine
'Inputs      :  N/A
'Outputs     :  Returns True if the timer routine was stopped
'Author      :  Andrew Baker
'Date        :  15/10/2000 15:24
'Notes       :  Code must be placed in a module
'Revisions   :

Function EndTimer() As Boolean
    If lTimerId Then
        lTimerId = KillTimer(0&, lTimerId)
        lTimerId = 0
        EndTimer = True
    End If
End Function

'Purpose     :  Starts the continuous calling of a private routine at a specific time interval.
'Inputs      :  lInterval           The interval (in ms) at which to call the routine
'Outputs     :  N/A
'Author      :  Andrew Baker
'Date        :  15/10/2000 15:30
'Notes       :  Code must be placed in a module
'Revisions   :

Sub StartTimer(lInterval As Long)
    If lTimerId Then
        'End Current Timer
        EndTimer
    End If
    lTimerId = SetTimer(0&, 0&, ByVal lInterval, AddressOf TimerRoutine)
End Sub

'Purpose     :  Routine which is called repeatedly by the timer API.
'Inputs      :  Inputs are automatically generated.
'Outputs     :
'Author      :  Andrew Baker
'Date        :  15/10/2000 15:32
'Notes       :
'Revisions   :

Private Sub TimerRoutine(ByVal lHwnd As Long, ByVal lMsg As Long, ByVal lIDEvent As Long, ByVal lTime As Long)
    Const WM_CLOSE = &H10
    Dim lHwndMsgbox As Long

    'Find the Msgbox
    lHwndMsgbox = FindWindow(vbNullString, zsMessageTitle)
    'Close Msgbox
    Call SendMessage(lHwndMsgbox, WM_CLOSE, 0, ByVal 0&)
End Sub

'Purpose     :  Extended version of Msgbox, has extra parameter to set time msgbox is displayed for
'Inputs      :  As per Msgbox
'               [DisplayTime]               The time in MS to display the message.
'Outputs     :  As per Msgbox
'Author      :  Andrew Baker
'Date        :  03/01/2001 13:23
'Notes       :
'Revisions   :

Function MsgboxOKDrop(Prompt As String, Buttons As VbMsgBoxStyle, Title As String, Optional DisplayTime As Long = 3000) As VbMsgBoxResult
    If DisplayTime > 0 Then
        'Enable the timer
        StartTimer DisplayTime
        zsMessageTitle = Title
    End If
    MsgboxOKDrop = MsgBox(Prompt, Buttons, Title)
    'Stop the timer
    EndTimer
End Function

Sub СамогаснущееОкно()
    lRetVal = MsgboxOKDrop("Это окно должно само погаснуть!" & vbCrLf & "Сейчас, через 5 секунд, окно погаснет!", vbOKOnly + vbInformation, "Самогаснущее окно", 5000)
End Sub