using direct x, so far i can detect the controller, poll it's state and return the values of the axes and 13 buttons. my goal was to be able to play steam games that don't normally support joystick controls, but everything i've tried so far is flaky at best (snedkeys). i'm thinking i need something lower level to translate the polled controller state to keystrokes + mouse clicks that another window can "hear"....

axis 1 value: -1000 = "A"

axis 1 value: 1000 = "D"

axis 2 value: -1000 = "S"

axis 2 value: 1000 = "W"

button 1 on: Spacebar

button 2 on: Crtl

button 3 on: Mouse.LeftClick

(You get the idea)

can anyone point me in the right direction? is this best set up as a service that runs in the background? any help would be mucho appreciated... i have a couple of side scrollers that are just begging to be played with a game controller (braid and trine)!

I use it with a wireless Xbox 360 force feedback wheel (with the wireless receiver) to play driving games on my PC that don't normally even work with wheels at all.

BTW I have no affiliation to the product, I just think it will do exactly what you need.

From the website:
Pinnacle Game Profiler is a keyboard keymapper, mouse emulator, game manager, and input device programmer—all rolled into one.

Pinnacle allows you to program what happens when you interact with your game controllers, keyboards, and mice. You tell Pinnacle which input devices to watch and how to react.  You have hundreds of commands from which to choose.

http://www.autohotkey.com/docs/misc/RemapJoystick.htm

I'm looking at remapping some buttons on usb joystick (in such way that they're still joystick buttons and not sending keyboard stuff) and it seems that writing either usb or hid filter driver is the only option (or intercepting directinput calls).