Creative colume control on Enhanced Keyboard not working properly

I've got a Dimension 8300 with XP on which I've recently done an XP reinstall.  Everything is fine, except that I used to have a Creative Audigy surround mixer on the "note" key of my Dell Enhanced Keyboard.  The correct mixer is SurMixer.exe. 

 

I have installed the Enhanced Keyboard drivers R44838, but this launches an application called mmkey.exe which is a different volume control and doesn't have all the Creative functions.

 

It used to all be fine with the Creative control before I reinstalled XP. 

 

Does anyone know how I can reprogram the "note" key to launch SurMixer.exe?