Lol I've done this years ago, not even hard to set up. Got bored of it coz it's pretty shit, can't half turn and buttons aren't like actual buttons so you press the wrong one quite often. Oh, and the input lag is so long!
Maybe you do it differently on the program you use. The one I used years ago, all you had to do was get a program on the computer, select the game file, then assign each button according to whatever keyboard configuration you use