No, sorry there is no way to find out the IP address of the unit unless you have access to it, and considering you said it was stolen, that seems unlikely. Generally when you see stories about how someone used the IP address to track down a stolen laptop, it is because they had a program installed to send that information to them via email that could be accessed independently of the laptop. It is one of those little details that often gets more or less left out of such stories, because it's highly technical and thus boring.
If your laptop has something like a cellular modem, you can report it stolen to the ISP and they can then check their access logs to see if anyone has been attempting to connect with it, and what cellular towers were contacted by the device to get a rough approximation of where the laptop is, but most cellular carriers will only do this sort of thing at the request of law enforcement.