You're right, you need to get the driver installed first, are you wanting this in the same script? Just that this would require a lot of editing each time you use a new driver. What might be a good option was to build a driver catalogue. This could just be a text or csv on a file share. The script would build an array of installed drivers on the client and compare the list with the central catalogue. If one is missing on the client, the driver could be installed, then the printer added.
Does this sound like the kind of thing your looking for?