I've already incorporated this into the final solution and posted it to my users (I didn't let on earlier, but this is only part of a larger script, the rest of which was already working).
Many thanks to Yvan for the final version, and for all those that got me/us here. Many thanks to J for posting Bill's pdf code, and to Simon & Luther for setting us off on the whole PDF track in the first place.
Cheers everyone, a job well done. Your help is massively appreciated! :)