I know on my G9 I can use the logitech software to assign the buttons as keyboard keys or macros. I think that's your only option. Pretty sure my old Razor had similar software for keybinding in case certain games wouldn't let you map the buttons in game.
FFXI:Sylph - Perrin 75 Hume THF; Retired (At least from my use any way)
EVE Online:ScraperX; Retired
WAR:IronClaw- Peryn SW;SkullThrone- Grymloc BO; Retired