title: How to replace word under caret position in richtextbox ? - implementing spellcheck suggestions
body: <p>I have a derived version of RichTextBox with custom spell checkers. They provide me a list of suggestions for a misspelled word.
  I would like to achieve the <strong>same correction functionality as in MS Word</strong>.</p>
  
  <p>If the users right-clicks a word, how do I get a string containing just 1 word?</p>
  
  <p>Once I have the list of suggestions, I would load them to the ContextMenu of the richtextbox.</p>
  
  <p>After selecting a word from the context menu, how do I replace the word?</p>
  
  <p>Note <strong>I cannot operate on whole TextRange(start,end).Text</strong>, because the RichTextBox contains objects other than text and they would disappear if I modify the Text property.</p>