Here's an example to try - it uses a user command 'getDPlocation' a temporary Global Table called "DPinfo" and this script:
Table t=Table.query("SELECT getDPlocation(Object) AS Location, Container, Class, DistAlongConveyor, Container, 'Conveyor::PhotoEye' AS NewClass FROM Objects() WHERE Class='Conveyor::DecisionPoint'");
t.cloneTo(Table("DPinfo"));
Table.query("DELETE FROM Objects() WHERE Class='Conveyor::DecisionPoint'");
Table.query("INSERT INTO Objects() (Class, Container,Location,DistAlongConveyor) SELECT NewClass, Container, Location, DistAlongConveyor FROM DPinfo");
ReplaceDPsWithPEs.fsm