From Use Case-based Sequence Diagrams to Code?

[Todd Rimes]

Apologies if there is somewhere better I should have posted this question, but most of the topics are so finite my simple question seemed to be out of scope for most.

I've spent countless hours making a use case diagram and my use cases are divided in to packages.  My use cases all have quite detailed Scenarios with alternate and error paths specified referencing Domain objects, other use case invocations, and Actors.  From within the Scenarios tab in the Properties dialog of each use case, I can generate Robustness Diagrams and Sequence diagrams.  I am NOT generating state diagrams as my project is a web project and there is no state between requests and all objects in the process of a request are used once and discarded. I AM saving and editing my Sequence Diagram messages such that "Fetch or create Account by email address" becomes getAccountByEmail() called on the Account entity.

SO my question is this: How do I generate code from the Sequence diagrams?  My experience in trying to do so is that I cannot, because my Sequence diagrams are "under" the Use Cases, not a Class model, even though the Entities and classes in my Use Case-based diagrams *reference* the Class model in my Domain model.

Do I cut and paste the Sequence Diagrams?  If so, then isn't traceability broken and if I have the same Sequence diagrams in two places, haven't I just created an update nightmare.

Up to now, EA has done everything I needed and I've been thrilled.  I just hope for a clearer understanding of how to get from Use Case to Code Generation.

Thank you,
~Todd