title: CTreeCtrl - only use checkboxes for certain rows/children
body: <p>I have a CTreeCtrl and I filled it with content. Now I wanted to add checkboxes but JUST for certain ones. I've found the possibilty to activate checkboxes on the TreeCtrl with <code>m_Tree.ModifyStyle(0, TVS_CHECKBOXES)</code>, but this adds a checkbox on each node/child on the whole Ctrl. Is it possible to turn this feature on, but just for certain ones?</p>
  
  <p>All I found is the possibility to add three different pictures, catch the clickevent on a node and change the image. Is there an easier way? Let me know. </p>
  
  <p>Thanks a lot,
  jntme</p>