This is a nice way to add exclusions to all of your Backup Exec jobs for common folders that are frequently locked, temporary files, or otherwise have a valid reason for exclusion from your backup sets.

BackupExec 11d
Edit > Manage Selection Lists
Select Excludes, click Edit

BackupExec 9.0, 9.1, 10
Edit > Edit Selection List
Select Excludes, click Edit

Syntax
To exclude the \Program Files\Symantec AntiVirus\SAVRT directory from all jobs regardless of their name and regardless of their drive letters:  \\*\*\Program Files\Symantec AntiVirus\SAVRT

Official Symantec (Veritas) article:  http://support.veritas.com/docs/264628