Custom ListBox control with Items Disable/Enable feature

I run once on a case where I have to show on a System.Windows.Forms.ListBox control some items that end user can not select, but still they have to be shown anyway since end user was expecting them. The point is that System.Windows.Forms.ListBox does not provide such feature, so I have decided to create my own user control and share it.

Here are some snapshots of the control at run time: