You could use the new Automation feature to run a script when a record is added.
Note 1 - The scripts in Automation are limited by run time (30 sec) and CPU use (1 sec? I believe) so more complex scripts will not work.
Note 2 - Since you are talking about adding a new record, this could be actually a much simpler script, just searching for a value from the new record in the target table to match. This could work depending on size of the database. It might be also possible to use Automation action Update instead of script, but I would have to check this one.