Are u using the TARGET Script Editor? If so the code below will make the mini stick operate the mouse. You will still need to assign Left, Right, Scroll up, and Scroll Down, from the UI_Layer to buttons on the Warthog.
MapAxis(&Throttle, SCX, MOUSE_X_AXIS, AXIS_NORMAL, MAP_RELATIVE);
SetSCurve(&Throttle, SCX, 0, 10, 0, 0, -4);
MapAxis(&Throttle, SCY, MOUSE_Y_AXIS, AXIS_REVERSED, MAP_RELATIVE);
SetSCurve(&Throttle, SCY, 0, 10, 0, 0, -4);
The Button name is "SC". Hope that helps.