Sorry if I am jst missng someting in forums or the intention of the Links tool

I have popped up a custom dialog box and listed pages within my site and can click the page names and enter into the editor the page name as a link to the page using PasteHtml 

what I really want to do is allow the user to highlight some text, popup my links dialog, have them click a page name and have their highlighted text become the link to the page

any syntax help would be appreciated