Getting rotating volume knob to work on HP keyboard

Question

My Apple keyboard recently stopped recognizing the Tab key, so I dug an old HP keyboard out of the closet, model #3502H ("Designed for WIndows 98" it says on the botton). I don't care about most of the spurious buttons scattered around the periphery, with the exception of the play controls for iTunes.
The stop, previous, play/pause, next, mute and eject button all work, but the volume knob, a rotating dial, doesn't. And I tweak my playback volume a lot during the day.
Is there any way to get this to function? I seem to have a vague memory of using this keyboard for a while under OS X 10.5 and the volume worked fine then, but not under 10.6.6 it seems.
If there's no way to force the OS to recognize the volume knob how can I assign F-keys to volume up and down? I looked in the Keyboard pref pane and those don't seem to be listed.
Thanks.

Answer 1

I wrote three Applescripts and saved them as applications (AppleScript Editor is in the Utilities folder). I use a program called FastScripts (free if you use less then 10 scripts I think) to assign them to function keys. It's not a perfect solution but it works most of the time. An example of when it doesn't work is when I'm playing a game that completely takes over the screen.
Decrease volume script:
tell application "iTunes" to set vol to sound volume
set vol to vol - 5
tell application "iTunes" to set sound volume to vol
Increase volume script:
tell application "iTunes" to set vol to sound volume
set vol to vol + 5
tell application "iTunes" to set sound volume to vol
Play/Pause script:
tell application "iTunes" to playpause