Additional feature "link-plugin"

I'm developing a CMS. Of course I use the excellent FCK-editor.

But, I have one question about the linkplugin. Users of my CMS are able to create an x amount of pages. I call them "Free Pages". In the browser, I request these pages with the following url: /freepage.php?page=BLABLA

Is it possible to adjust the link plugin in order to have a select list with all the 'free pages' a user has created? And when a page is selected, the linkdialog returns the value ".... href="freepage.php?page=TEST".... ?