Well, solved by myself. it's a bit tricky and, i think, only works for some hawey keys (because kernel support). All you have to do is edit the file /etc/ppp/chat_DeviceHW_E220.conf and change the line OK AT+CGDCONT=1,"IP","your_APN_here".After that create a new 3g connection in the wifi setup, and select the E220 device.P.S. It is supposed you have your key modem connected in a USB port.