if you are able to get him to agree that he'd pay for college in writing, then great, but legally you can't make him, I tried to do that but both his and my Ls said that once kids are over 18, college tuition is not mandatory for the dad to pay. Fighting him for it might not get you anywhere. It'd be good if these men would agree to be decent fathers, but, whatcha going do..
I think it depends on what State you live in, I have known people who have gotten that done in Court based on the agreements signed in the Divorce Decree. Its a legally binding contract. If he refuses, take the balance of the tuition out of his ass. I'm a big fan of the Godfather btw..... LOL