Backup-to-Disk folders and Overwrite question

Hello,

I am using Backup Exec 12.5 on SBS 2008 and have a monthly full backup job to a Backup-To-Disk folder. I understand how to setup the media for overwrite and append but have a question about overwrite. If I set this job media to overwrite after 1 year will it overwrite all 12 monthly backups? My goal is to always keep 1 year of backups from this job and have it just overwrite the oldest month. Is this even possible with BE 12.5?

Thank you.

Steve