Search this forum for 'barcodes' and 'bar codes'
This topic came up about a year or two ago. You might have to look for older articles to get this answer.
Since Word has this ability, it is possible that an element of the Word library would generate a bar code for you if you could just call it at the right time. So you might wish to look up that topic in Word help in the "Programming" topic. Perhaps there is a callable function for it. If so, you can call anything from Access VBA that you could have called from Word VBA. (Just have to make the references right in the code windows tools >> references path.)