You can add your own war goal from the target country's diplomacy screen (while viewing war progress), if your country has sufficient "Jingoism", but that often requires sieging a country to the brink of total occupation until you get enough public support. Hover over the box (between the country's prestige points and its infamy, shifted toward the right), and it should show how much Jingoism you need and how much you have at present. Normally, the AI will accept the existing surrender conditions long before that becomes a viable option. As said, you also pay full infamy to place the war goal, and the war leader is very likely to simply ignore it when settling the war.
It CAN happen, but it's an extremely unreliable way of gaining something.
In a loosely related situation, I wanted to take a province from another major country, but every time my truce with them expired, another crisis happened before I could formulate a CB, and then I was stuck with another a 5 year truce until just before the NEXT crisis. Stupid idea, for whoever figured that 5 years was the right cycle length for both crises AND for truces. Ultimately, I had to take the nasty prestige hit for not getting involved in the crisis (dropping my national rank almost out of GP status), then declared my war after the crisis was resolved.