Hi Peter,
These two fields seem to be what you are looking for, if you're not using Timesheets:
EXTERNALTRANSNO NUMBER YES For a transaction that is from a time entry, this refers to PRTIMEENTRY.PRID. For imported transactions, this could be a unique ID from an external system.
EXTERNALBATCHID VARCHAR2 20 YES The External batch ID as specified in the XOG or timesheet. When a timesheet is posted, EXTERNALBATCHID=PRTIMESHEET.PRID and the EXTERNALTRANSNO field is blank.
Please check them out and see if that could be a good solution for you.
For PROJSITE column : FYI I raised a defect:
CLRT-79212 PPA_WIP.PROJSITE column does not get deleted when upgrading from 7.5.3>8.1, and column remains in the database when upgraded to 14.x
Please let me know for any questions.
Kind Regards
Nika Hadzhikidi
CA Technologies
Principal Support Engineer