The first thing to clarify would be whether the customer would be running the "year end" on 12/31, or on 01/01.
If it can be run on 01/01, you could simply set up "Advanced Retention" in the current Retention Policy and specify the appropriate expiry (or lack thereof) for the yearly tag as well as whatever the current retention is for the "daily" backups - this lets you use the current Group/Policy by just modifying the retention component.
If they have to run it on 12/31 (or any day other than 01/01), it will be a little more complicated - you will likely need a specific group/policy with its own specific retention policy and a specific schedule that runs the job on 12/31.
Thank you for the response - since the backups had already occurred, and per the advice of EMC, ended up going into the backup, restore and manage tab. I then clicked on the client on left side, then manage on the right side, then checked all under by retention.
It listed all of the backups and their expiration dates etc. for that client. Then on the right side I chose the latest backup and right click, change expiration date, then reset it to years from now. That was the solution here, hope it helps anyone else with this project.