Great suggestion. An aquaintance actually emailed me that same suggestion late last night. Specifically, since my PDFs are generated on the fly from a set of MS Word templates, he suggested I create a static PDF with a barcode field on it and then copy that field from that static PDF after setting the correct value.
Not sure it'll let me do that, but I will give it a go and post back.
George's points cause me to reconsider (and use) a 1D solution, but I'd still like to figure this 2D thing out.
Thanks all.