How to bind to zoom slider on Microsoft keyboard

Recently, I acquired a Microsoft Wireless Comfort Keyboard 4000 at a garage sale. Among other interesting features, it has a zoom slider.

Naturally, the slider (along with most of the shortcut buttons, except for Calculator, Sleep, Mail, and Web/Home) no longer works. Somewhat surprisingly, however, it does not even register as a keyboard event when I try to bind it to stuff. It’s probably not a hardware issue; the keyboard is still in good condition, and all the buttons you’d find on a normal keyboard (QWERTY, carriage return, pause/play, etc.) still work.

Is there any way to get it working again?