Hi there,
You are pretty much stuck here. Even the cheapest double button joystick will be better than keyboard. In all honesty go out and find the best joystick you can afford. CH is good, Thrustmaster, Saitek and MS products are all being used. If you can get it a set of rudder pedals would be a big help in flying over just a joystick alone.
AH rerally cannot be enjoyed without a stick. It is pretty hard to fly much less be competitive with just a mouse. Get a stick and learn to fly!
Mav