Evaluation Time AUTO is not allowed in Barcodes

[e.sanclodio]

Hello,
My problem is the following:
I have to send letters with a variable number of sheets depending on the client (the letters for multiple clients are created in the same PDF document).
These PDFs are then sent to a machine for printing and enveloping, so for that each letter can be enveloped, it is necessary to include information in a bar code that the machine itself reads.
This barcode you needs:
 - The current sheet number of the letter you are printing
 - The total number of sheets of the letter
 
So far so good, I have solved it with the variable Page_number and a local variable currentPage as explained in the iReport manual "Page X of Y" using a single text field
Both values ​​are correctly

seen in the expression, the problem is that when introducing the expression in the barcode, the Evaluation Time = AUTO is not allowed in it and without that property it does not work well.

Thanks for your help. Regards, Edu