how to get real ip?

[710]

Hi...recently I have bought a new router so my laptop can have internet connection.I host call of duty 4 server....but after connecting to internet by my router I have understand that my pc or my laptop doesn't have a real IP...the ip now I have it is made by my router..but my router has the real IP I had ones...So I cant use this soft and share my files with others (http://www.rejetto.com/hfs/?f=dl) when I run it it shows the fake ip address given by my router..A friend of mine suggested that I nned to port forward the soft I am using by my router or something..BUt I am confused cane some one help?