From the begining, when I installed the Feisty Fawn I noticed that the 2.6.20 kernel recognized the E220 usb-serial modem... So what was still to get through was the modem configuration to have pppd establish the connection to my ISP provider.
After I understood what the problem was that make the pppd died while trying to establish the connection, was an easy task to get it going.
So, now that I understand already all the steps involved, I have another option for getting a linux router/firewall (at least with the 2.6.20 kernel -- I stiil will have to go back and see when the E220 started to be supported) connected to the Internet and give an internet access anywhere it is necessary.
More and more liking the freedom I get from working with something I realy can study and understan (even under the hood!) and where I can relly upon without having the fear of not having support!