Help ReselectText

I need to allow the user to select text in a CEditView and then once I GetSelectedText (I can do that part and ReplaceSel) I want to replace this text with0new text and reselect from the start pos which they orig selected to the new end position. How might I do this? Also I want to have toolbar items that are not enabled until the user selects text in a CEditView how might I do
this? Thanks for any help