[exim] Log stats to DB?

All,

Can someone share an Exim rule that will allow me to log statistics to a
database? I want to log the number of messages sent to/from a given
user, total messages sent through server, and other various data.

I've got Exim connected to PostgreSQL currently and can do queries
inside routers / transports etc to qualify 'senders =' and lookup data
with 'data =', but I haven't figured out how to just exec a query for
the purpose of simply logging.

Any pointers would be appreciated. Using Exim 4.63 here.

-- Dante