Imports System.Text
Public Class Form1
    Declare Auto Function FindWindow Lib "user32" (ByVal lpClassName As String, _
      ByVal lpWindowName As String) As IntPtr
    Declare Auto Sub GetDlgItemText Lib "user32" (ByVal hDlg As IntPtr, ByVal _
    nIDDlgItem As Int32, ByVal sb As StringBuilder, ByVal nMaxCount As Int32)
    Private WithEvents Btn As New Button With {.Dock = DockStyle.Bottom, .Text _
    = "Start", .Parent = Me}
    Private WithEvents T As New Timer With {.Enabled = True}
 
    Private Sub Btn_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Btn.Click
        MessageBox.Show(Now.ToString, "MsgBox")
    End Sub
 
    Private Sub T_Tick(ByVal sender As Object, ByVal e As System.EventArgs) _
      Handles T.Tick
        Dim Hnd As IntPtr = FindWindow("#32770", "MsgBox")  'DialogBox und 
        ' Titeltext
        If Hnd <> IntPtr.Zero Then
            Dim sb As New StringBuilder(256)
            GetDlgItemText(Hnd, &HFFFF, sb, sb.MaxCapacity)
            Me.Text = sb.ToString
        End If
    End Sub
End Class
 
MfG GPM

<DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
Private Function GetDlgItemText(
    ByVal hDlg As IntPtr, _
    ByVal nIDDlgItem As Integer, _
    ByVal lpString As StringBuilder, _
    ByVal nMaxCount As Integer) As Integer
End Function