Creating barcode images
I have found my answer!
By using the barcode generator www.barcodesinc.com I generated a URL and input this into my email.
Eg: http://www.barcodesinc.com/generator/image.php?code=999999999&style=197&type=C128B&width=200&height=50&xres=1&font=3
I then changed the 999999999 in the URL to my conditional code to change to the specific code for that person and also bring back the barcode image for that code too!