Dell True Mobile 5100 GPRS PC Card & AT&T

I had to travel abroad (Europe) and would like to use my Dell Inspirion there on the local GSM/GPRS network for Internet acsess. Can anyone tell me if this is possible with just a local SIM card and some decoding of the Dell True Mobile 5100 GPRS PC Card (AT&T service) ? And if possible shall I call Dell or AT&T for this ?