Slide 1 of X: a solution for PowerPoint numbering

I just spent a frustrating half-hour on a search that isn't really part of my job but I couldn't resist the challenge.

On an email group here at work, someone asked how to get PowerPoint to automatically number the slides in a "X of Y" format. So, I opened a new presentation and started fiddling with the master slide. Slide number, simple. But no way to modify its format.

(Here's an oddity - to change the starting slide number, you go to File -> Page Setup.)

There had to be documentation of the appropriate field code somewhere, yes? Well, I sure couldn't find it. Finally I went back to my Inbox, and at the end of a chain of emails, two people found a solution: PPTools introduces and links to Bill's SaveSelection add-in for PowerPoint.

Now I can focus on work again.