Hi,
In this special case I use method in external assembly: call method with two parameters AA and BBB and get as response (through DAL) – my identificator.
If you have no need in some external helpers – (actually I use WCF-SQL adapter – call SQL through generated schemas) – or you can expose as it is most suitable for your architecture.
If you have distributed envoronment – you can expose it even as web service – availiable for all your “different projects”