The best option is to get rid of the repeating fields. If you use a portal or portals to a related table with one portal row in place of each repetition, this problem will no longer exist. It's relatively easy to convert a set of repeating fields into a set of related records using import records.
But if you insist on repeating fields, the Get ( ActiverepetitionNumber ) function can be used by your script to determine what repetition to modify with the current date.
Thanks, Phil, I knew I was in for the "if you insist", and I agree. I'll have to work on the original owner of the data base.
But thanks for the alternate solution. It sounds like what I was looking for.