Look for the documentation for EN_SELCHANGE. That is sent if you ask for it (read the page for details), and then you get notified when the selection changes. That was you handle the user clicking in different places, and update external stuff if you so wish. If you just want to know when your view is clicked on to wake it up, you can make a new view vlass inheriting from CRichEditView and handle override CView::OnActivateView. Good luck, Iain.
In the process of moving to Sweden for love (awwww). If you're in Scandinavia and want an MVP on the payroll (or happy with a remote worker), give me a job!