Did they setup the server or are you just renting the server space and you installed it?
What is the IP of the server?
I ask because there are two types of IPs: private and public
Private IPs are not usable and have a few different ranges:
192.168.0.0 - 192.168.255.255
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
Anything in that range will not be accessible on the internet. It is unlike that that's the IP but I thought it might be an idea.
If it happens to be... you will need a public IP to connect to. Usually the router will translate between a private and public IP so if you have the private one you may just need to find out the public one.
Also, can you talk to the people who you're renting from and ask them for help?
EDIT: You may get a better response from this in the Tech Help forum. I'm sure there's a few gurus from that area who don't frequent here.