Erhh, put all the other sh*t in the same spot.. can't say I ever heard of that.
How old is the dog? It's very hard to train this once they are older that say 4-5 months and impossible without a kennel/den.
All dogs should have an enclosed kennel, a 'den' so to speak. Dogs don't sh*t in their own den except out of desperation. Dogs can hold it for a long time.
AT times they are alone once they are off suckling, a dog should be put in its own kennel, and only let out to play, eat and sh*t.
Once they are confined there for a long time, when released they will need to go, get a short leash and you take them to the spot you want them to go. Hold them on the leash and don't let them roam.
They will eventually go on that spot where you have taken them.
Once them finish, reward them... lots of positive tones a pats, even a treat like dried kidney.
Later on the positive tones will be enough.
They will get the idea thats where to go.
You do have to clean the area of course, they won't return if there is mounds of dried crap there.