Adding links to HTML for a CMS

Hi, I am trying to create my own CMS. To being with I want to let users edit anything within a <p> tag. I want to have a menu to the left and display the webpage in the rest of the page, and for each set of <p> tags I want the user to be able to click on the link to edit that paragraph. My problem is how can I include a webpage in my CMS and for each <p> tag wrap an <a href""> tag araound it? Thanks for your advice.