Long-distance access

I have admin login and password from internet cafe with winxp on computers. I have the IP adress of the one computer too. Ive tried to get a long-distance access trough telnet, but the IP adress has no alternative name. Why? (For example: www.yahoo.com-216.109.118.69)
But when I type the IP adress to DNS lookup in wwwhack, I become answer (unknown).
Can somebody tell me, if I can have long-distance access from my PC with these informations?
And if not, what I have more to do? And can you tell me, why some PC's dont have alternative IP adress? I am sorry, if these questions are stupid, but I am a beginner and I want to know these things.

Did it occur to you maybe using an internet cafe' login and password to access the machine remotely without permission may be illeagal. From what i understand antionline does not promote this type of activity and nor do i.
As for the ip problem: most places will have a nat router and non routable ip addresses assigned that the computers inside the network use.