Hi Jason,
Thinking about this why not break it into two problems.

1. Making a virtual column called AFFECTED or something which contains
the number of rows affected by an insert, update or delete sql
statement.

2. Implement the returns or returning portion of insert, delete and
update statements such that you could write insert into mytable ..
returning AFFECTED, PRIMARYKEY that has been also discussed as possible
in Firebird.

Would that not give you more flexibility if available in the trigger
language, stored procs and sql?

Regards
Ian Newby