The third option - image file embedded - is viable. You can use any third-party application to generate these. You could also use Word 2013 and a screen capture utility to generate such images for use in Word 2010.

Office 2013 introduced the DISPLAYBARCODE and MERGEBARCODE fields which handle this easily. Word 2010 has no native way to generate or use these fields.

Here is a link to my free Add-In which generates such codes in Word 2013 or later: Bar Code Add-In. You do NOT need the Add-In to generate these codes, though.