Unless ginawa ng developer na may mouse and keyboard support yung game like cs:go kailangan mo bumili ng Eagle Eye by Penguin United. Be warned na hindi sya perfect mouse ang feeling since simulated lang ang mouse but I think it would be the closest you can get as of now, for best experience take your time tweaking the settings plus buy a good gaming mouse (logitech g500 ang recommended ng users).
Alternative to Eagle Eye is XIM3 originally for Xbox360 pero alam ko may adaptor to for PS3 mas mahal sa Eagle Eye since may screen sya, mas advanced daw in terms of simulating the feel of the mouse, and bibilhin mo pa yung PS3 adaptor. Cheapest alternative would be Hori Tactical Assault Commander 3 since hindi ka na bibili ng mouse and keyboard, although from some reviews na nabasa ko hindi sya as flexible to configure as the other two.