I have an application with a transaction record that has a lookup field to an employee object.  The name field in the employee object is the employee id.  We'd like to create our own lookup search page that allows the user to enter the employee name instead of the id.  This is similar to the filter functionality only it would be the initial search.  We know how to customize the lookup page but we would like to add a button, similar to the lookup icon, to the edit page to invoke our custom code.  Unlike display pages, it does not appear that you can embed a piece of Visualforce code on an edit page.  Do we really have to recreate the entire edit page in Visualforce or are we missing something?