With the System.Windows.Forms.RichTextBox, yes, you have to do your own code to figure out the word given a location. If you use the Windows Presentation Foundation (WPF) RichTextBox, there's some built-in things to help you get the run/word/paragraph at a particular point, IIRC.
Tech, life, family, faith: Give me a visit. I'm currently blogging about: The Virginia Tech Shootings, Guns, and Politics The apostle Paul, modernly speaking: Epistles of Paul Judah Himango