Mittels API-Aufrufen kann man das aktive Fenster ermitteln

ERFORDERLICHE OBJEKTE

   1 Label (Label1)
   1 Timer (Timer1)
 FORM-CODE

   Private Declare Function GetWindowText Lib "user32" Alias _  
      "GetWindowTextA" (ByVal hwnd As Long, _
      ByVal lpString As String, ByVal cch As Long) As Long

   Private Declare Function GetForegroundWindow Lib _
      "user32" () As Long

   Private Sub Form_Load()
      Timer1.Interval = 200
   End Sub

   Private Sub Timer1_Timer()
      Dim hWn As Long
      Dim Titel As String * 255
      Titel = String$(255, 0)
      hWn = GetForegroundWindow
      GetWindowText hWn, Titel, 255
      pos = InStr(Titel, Chr$(0))
      If pos > 0 Then Titel = Left$(Titel, pos - 1)
      Label1.Caption = Trim(Titel)
   End Sub