By Tom SpeirsExample AddIn with full source code.
AddIns allow programmatic creation of custom modules (lists and menus) in GameEx. New in 2017. For extending GameEx to launch, list and play anything.
You can also download the file here if you do not wish to register with the forums or do not have a paid subscription.
You can configure and enable (and also download) Addins with the Repository Manager utility included with GameEx.