If you are trying to make Dulce De Leche in a can then you will need Sweetened Condensed Milk. That is the only thing I can think of that makes a milk desert in a can. My sister puts it on her ice cream.
Edit: you take the label off the can and cover it with water and bring to a boil turning the can ever so often. Sorry I don't know exactly how long you boil it for though. Just be careful because heating things in a sealed can can be dangerous. I have never heard of the milk exploding like veggie cans do though.
