You can launch the Pattern String Builder from the Argument Builder editor when the Unique Name token is selected. The Argument Builder editor pane shows a Pattern field where you can click to launch the Pattern String Builder.
Figure 16-6 Unique Name Token in the Argument Builder
Click the Edit patterns icon to launch the Pattern Builder.
Specify the pattern or click the Edit the arguments icon to use the Argument Builder to create the pattern.
Click Finish.