Adding new effective dated row with a Component Interface

Hello. I have a flat file with Position data that I must load into HCM. The file contains a mix of 1) new positions and 2) existing positions that have a new effective dated row. I am using a File Layout to capture the fields from the flat file. Then I store them in a state record. I created and App Engine and dragged the delivered Componment Interface over to create the PeopleCode. I modified it successfully so that it creates the new positions. The problem is with the existing positions. For example, I have position XXX01 with effective