My mind is mush! (must be the holidays).
Is there not a one line SQL statement or expression for an APPEND FROM that updates a table with records from another identical table which don't exist in the first table?
Something like....
USE A
APPEND FROM B FOR B.keyfield NOT EXIST(A.keyfield)
--- Larry
-- Larry Keyes
Remember only You can prevent Gray Goo. Never release nanobot assembers without replication limiting code.