To Create a Custom Output File Name Expression for a Print Set

In the Print Organizer dialog (File > Print > Print Organizer), select File > Output File Names.
The Output File Name Expression dialog opens.
Select a predefined expression that is similar to the one you want to create.
The contents of the expression are shown in the dialog's read-only Expression field.
From the Expression name list, select Custom.
Make the necessary modifications.
(Optional) To preview the expression, click Preview Names.
The Output File Names dialog opens to display the new output file name(s), if you have files in the active Print Organizer session.
Click OK.
The Output File Name Expression dialog closes.