Is there a reason why you want to do this? Most specialist positions require general expereince first, which I think is good for two reasons - what you want to do in theory may turn out to be really different when you actually get on the floor, and you never know what's going to come up so having a broad-based general knowledge will always help.
Did you have some particular career path/goal in mind?
Maybe I don't understand the question. But you specialize by working in an area. You can't just suddenly become a specialist in anything without first working there. You can get a job in a specialty area as a new grad (altho I don't recommend it), but you can't just "become" a specialist without a little work first. That is like saying you want to fly to the moon first and then become an astronaut. You have to crawl before you can walk.