You can use the editors StripAnchorPaths
property set to true
to strip the page's domain but it will be applied only when the editor's content is saved. So, you will have to go trough all the pages.
What we suggest and believe that will be the best approach is to write a SQL Query that will change all urls in the DataBase - unfortunately we cannot provide the desired code. The best place to ask for such a query is the SharePoint Server 2007 Developer Portal
the Telerik team