To be able to send 100 SMS messages to a single number, a bulk gateway is required. However, these gateways are not free and you actually have to buy the rights to use them.
There is a service called BulkSMS where you can buy SMS packages to send: http://www.bulksms.com/pricing/
Note: Before sending the messages, check the country of destination because the price per volume differs based on the receiving country.
