there are a couple of issues with your approach, but maybe this will help.
Using a consumer SIM from a mobile operator won't usually give you a static IP address, so the IPconfig / all is only telling you a DHCP (temporary) address you have for that session.
To setup a 3G connection, you don't usually need to enter the phone number anywhere - there are standard AT commands that you need to send (see a device development guide on this site as a good starter). You'll need to know the APN (access point name) that you want to connect to.
You can usually get some expert advice and a service that is designed for your type of service from your local network operator. I know some people who have worked with Telstra in Australia and have been pretty successful, maybe it is worth you speaking to them.