Private Sub lstKom_MouseDoubleClick(ByVal sender As Object, ByVal e As _
  System.Windows.Forms.MouseEventArgs) _ 
Handles lstKom.MouseDoubleClick, lstKom.MouseDown
'// 
End Sub

Private MouseDownTime As Date = Nothing
 
[...]
 
Private Sub lstKom_MouseDown(ByVal sender As Object, ByVal e As _
  System.Windows.Forms.MouseEventArgs) Handles lstKom.MouseDown
        MouseDownTime = Now
End Sub
 
Private Sub lstKom_MouseMove(ByVal sender As Object, ByVal e As _
  System.Windows.Forms.MouseEventArgs)
        If e.Button = MouseButtons.Left AndAlso _
             (Now > Me.MouseDownTime.AddMilliseconds(200)) Then
                  lstKom.DoDragDrop(lstKom.SelectedItem, DragDropEffects.Copy)
        End If
End Sub
 
[...]
 
Private Sub lstKom_MouseDoubleClick(ByVal sender As Object, ByVal e As _
  System.Windows.Forms.MouseEventArgs) Handles lstKom.MouseDoubleClick
         MessageBox.Show ("It works!")
End Sub