the lidded boxes are a blessing for those of us whose cats stand up to pee (not limited to boy cats, sadly). He is probably coming in to pee cos that is what be believes the box is for, so if you gradually move one closer to the door, then outside he will more than likely use it until spring when your neighbours start digging up their flower beds and he discovers the joys of toiletting au naturel!! The lidded boxes usually also have a flap entrance which you will need to take off to start with as not all cats understand flaps unless they are also used to a cat flap. Try placing a cardboard carton over the litter tray (with a hole cut big enough for him to get through) to see if he would adapt before lashing out any buying one. They are quite expensive.
