Sharing code behind between Pages and User Controls

Hi. This will come across as a bit of a newbie question but...
My site has a number of similar pages. Virtually every page on the site references a single shared code behind file - DefaultPageHandler.vb. I also use a number of user controls that handle the data entry of certain fields - e.g. a single user control that handles entry of name and address that is referenced by several pages. Each user control references another single code behind file UCDefault.vb which, at present, contains no significant code at all.
I am developing a user control that requires a bit more intelligence. Ideally I want to be able to call logic from it that is already available within DefaultPageHandler.vb but I can't just change the user control .ascx file to include "Inherits DefaultPageHandler" because DefaultPageHandler contains the line "Inherits System.Web.UI.Page" rather than "Inherits System.Web.UI.UserControl" so it triggers a compilation error ...