extra settings in modem configuration

i allready typed ATX1 in my modem extra settings in control pannel to connet internet. I want to add one more string to enable my modem for receiving the callerid information. I need to add ATVCID = 1 or ATVCID = 2. How can i add the Two Strings ATX1 and ATVCID = 1, And also i use the same modem to connect the internet (Dial up).