If you just want the font and be on your way: Here it is
In past lives I have done a lot of work with barcodes. Usually, because it's a job, I could fund getting actual good barcoding plugins to get the job up and running quickly. I have done a lot of searching for free ways to make barcodes and they do exist and some are quite good. However, they always end up costing time instead of money. But you could say that about the ones that aren't free as well. Recently I had the need to get a barcode in Excel. Which first off why does Excel not have barcode support out of the box! Or off the disc as it were. I mean if they had just spent all the time they wasted making Clippy and added functionality that people could actually use... Anyway, I did in fact track down an good, very free, barcode font for 3of9. I don't know that I have ever used a barcode scanner that didn't read 3of9. It's not the slimmest of barcode options but it's free and you can get barcodes added to a document or in a project quickly. So I thought I would share it.