I use a program called "Joytokey" that sits in the system tray, and converts any joystick/gamepad/wheel button press to a pre-assigned keyboard command.
This would make it possible to have 2 buttons for 1 command. Just assign both buttuns to the same keyboard command. Easy.
The other positive of this, is that I can have certain buttons on my wheel for F9, F12, H, Shift+R, Shift+S, etc. etc.
Another positive, is that I can have L3 and R3 as "alternate" buttons.... I.e. when L3 is held down, the rest of the buttons take on a different function, effectively trippling the amount of buttons
PS: You might be able to manage something similar with the Logitech Wingman Software...