Option Explicit
 
'Konstanten für Mausklicks
Const MOUSE1 As Long = 1 'Linke Maustaste
Const MOUSE2 As Long = 2 'Rechte Maustaste
Const MOUSE3 As Long = 3 'Mittlere Maustaste (kein Mausrad)
Const MOUSEWHEEL As Long = 4 'Mausradklick
Const Mouse5 As Long = 5 'Mouse5 (bei Logitech: Zurück)
Const Mouse6 As Long = 6 'Mouse6 (bei Logitech: Vorwärts)
'Konstanten für die Berechnung
Const TPP As Long = 15 'Twips -> Pixel Faktor
Const COLUMN_HEADER_HEIGHT As Long = 16
 
'Hier wird die Höhe der Titelleiste gespeichert
Private TBarHeight As Long
 
'Types
Private Type POINTAPI
    X As Long
    Y As Long
End Type
 
'API-Deklerationen
Private Declare Function GetAsyncKeyState Lib "user32" (ByVal vKey As Long) As _
  Integer
Private Declare Function GetFocus Lib "user32" () As Long
Private Declare Function GetCursorPos Lib "user32" (lpPoint As POINTAPI) As Long
 
 
Private Sub Form_Load()
    'Init GetAsyncKeyState
    Dim i As Long
    For i = 0 To 255: GetAsyncKeyState i: Next i
End Sub
 
Private Sub Form_Resize()
    'Höhe der titelleiste herausfinden
    TBarHeight = (Me.Height - Me.ScaleHeight) \ 15
End Sub
 
Private Sub Timer1_Timer()
    Dim hFocus As Long 'sicherstellen, dass der Focus innerhalb unserer
    hFocus = GetFocus 'Anwendung liegt
    If hFocus = Me.hWnd Or hFocus = ListView1.hWnd Then
        If GetAsyncKeyState(MOUSE2) And &H1& Then 'Prüfen, ob MOUSE2 gedrückt 
        ' wurde
            Dim m As POINTAPI
            GetCursorPos m 'Mausposition abrufen
            'Mausposition prüfen
            If m.X > Me.Left \ TPP + ListView1.Left \ TPP + 6 _
            And m.X < Me.Left \ TPP + ListView1.Left \ TPP + _
            ListView1.Width \ TPP + 2 Then
                If m.Y > Me.Top \ TPP + ListView1.Top \ TPP + _
                TBarHeight And m.Y < Me.Top \ TPP + ListView1.Top \ TPP + _
                TBarHeight + COLUMN_HEADER_HEIGHT Then
                    MsgBox "jo"
                End If
            End If
        End If
    End If
End Sub

Mit freundlichen Gr??en,
Andy G.