From an agent, I don't think so. But, if you run it from command line and point to the replica database... And assuming this replica database is an exact replica of master DB, it may work. The BIX command line process would need to be able to successfully start the engine using the data in the replica DB. You would just need to configure the command line process to point to the replica DB. One problem I can think of is that this will update tables in the replica database. For example, the extract will write to a table in order to track the last time the extract ran. If the DB user in use does not have permission to update tables, I'm not certain what the outcome would be.