There may be a need to add box serialization in the form of "Box 1 of x" to your label. BarTender has an object called the "X of Y" component that uses Visual Basic Script for this purpose.
With BarTender open, choose the Components ToolBox. If this is not visible, choose the View menu and enable Components in the ToolBox area.
In the ToolBox, expand the Serialization folder. Look for Label X of Y.
Equally, you can place the Component X of Y in the following folder: My Documents/BarTender/Components
Drag the X of Y component onto the label. The component is now ready for use, but you may want to customize the text to meet your needs. Open the component properties and examine the data sources. You can modify the "Label" Data Source, but do not modify the other data sources or you risk breaking the component.
The component is controlled through the serialization transform, or from within the print dialog.
Set the Serialization option to your maximum Y count, i.e. x of 500, and select print. The labels will print with your incrementing value until it reaches the high number of the serialized value.
You can download the final document here: XofYsample.btw