Well not really a mouse has a motion sensor 3 buttons and a roller a joystick has umteen buttons and usually a dpad and a couple of analog sticks. It all about drivers, the game isnt set up to take input from a controller so you cant use one.
Besides you really wouldnt want to, for fps games the keyboard and mouse is far superior to the control pad. You would get killed no bother, they usually slwo down games for consoles compared to their PC counterpart to give you time to work the controller. So stick with a keyboard and mouse, the only games you get an advantage using a controller are beat em ups and they dont have many of those for the pc.
So it wont work its not a case of tricking it into thinking you are using a mouse, if it says mouse only it means mouse only.