is there any way to do something like a mail merge, where the data (9-15 chars long) is converted to a barcode? im using trying to use openoffice's code128 for calc, but for some reason, every 10 strings, the barcode goes crazy, and the ascii tells me to register at the site where the extension came from, which i dont want to do

i also found one for oodraw, but that requires the values to be inputted manually. since im not familiar with the macros, i can't write something that will do it automatically

what im trying to do is:

take an old pdf (only 1 page)
covert it to word or picture or something
add a function/macro/whatever to show a barcode 
        (whether or not the barcode shows in this file, i dont care), 
        given a string from excel data
reconvert to separate pdfs

or some other way that adds barcodes to pdfs

all other free programs i have found do not do this nicely, and since im not really a pdf person, im not going to buy random programs. i just need this done for one large batch of data