thats exactly what i did.  i have the logitech g11 and i have little macro buttons for everything.

    ;audio switch
    !^+s::
      toggle:=!toggle ;toggles up and down states.
  Run, mmsys.cpl
  WinWait,Sound ; Change "Sound" to the name of the window in your local

language
  if toggle
    ControlSend,SysListView321,{Down 1} ; This number selects the matching

audio device in the list, change it accordingly
  Else
    ControlSend,SysListView321,{Down 2} ; This number selects the matching

audio device in the list, change it accordingly
  sleep 100
  ControlClick,&Set Default,Sound,,,,na ; Change "&Set Default" to the name of

the button in your local language
  sleep 100
  ControlClick,OK,Sound,,,,na
return