Would you be able to supply a snapshot of what the label looks like so we can get a better idea?
And oldschool is 100% correct when he mentioned not all printers will bar code properly. Those ink jet printers that everyone has simply won't do the job. Sure, the output looks VERY close, but lots of shipping companies scanner guns can't read it for some reason. The bar coding must be done in a very fine detail.
To accomplish this, either a Zebra printer is required (very common for bar coding) which happens to use 'heat' to make the print, or a good laser printer.
Maybe start or move this thread to the computer section and post a pic of the label you're trying to reproduce, plus the standard run quantity. Each detail will be very important to get the most bang for your buck.