Print control lines on a report for scanning by a machine

I have a report which prints customer statements at the end of a month. The report is about 2000 pages in length, and each customer may have from 1 to 5 pages in his statement depending on the number of items he has ordered. The pages on the customer statement are numbered 1 to n and each time a statement for a new customer is started, the page number is reset to 1.

These statements are presently being separated and folded by hand and stuffed in envelopes for mailing. We are looking at buying a machine into which we can feed the statements and the machine will group the pages for a customer statement together, fold them, and stuff them into an envelope for mailing. In order to do this, the statements must have control lines added to it to denote first page of a statement and last page of a statement. These control lines are 2 points thick and a half inch wide similar to the following. ( ── ) The distance