lstTab_SelectedIndexChanged(Me, EventArgs.Empty)

    Class SelectedIndexEventArgs
        Inherits EventArgs
 
        Private _selectedIndexChangedParams As Object
 
        Public Sub New(SelectedIndexChangedParams As Object)
            _selectedIndexChangedParams = SelectedIndexChangedParams
        End Sub
 
        Public ReadOnly Property SelectedIndexChangedParams() As Object
            Get
                Return _selectedIndexChangedParams
            End Get
        End Property
    End Class

lstTab_SelectedIndexChanged(Me, New SelectedIndexEventArgs("Meine Daten"))

Private Sub lstTab_SelectedIndexChanged(sender As Object, _
        e As System.EventArgs) Handles lstTab.SelectedIndexChanged
 
    If TypeOf e Is SelectedIndexEventArgs Then
       Dim siea As SelectedIndexEventArgs = DirectCast(e, _
         SelectedIndexEventArgs)
       Dim mydata As Object = siea.SelectedIndexChangedParams
 
       '.........
       'MyData wäre ggf. weiter zu casten - oder man verwendet eine spezifische 
       'Eigenschaft in der SelectedIndexEventArgs-Klasse
    End If
 
End Sub