What are the parameters needs to be configured for sending udp data from one to other network

For one of our application , the dhcp integrated switch assigns ip address for the wiznet . It is something like 172.16.1.100 as source address and we are supposed to send udp data packet to destination address 239.18.1.1.

with default settings , by broadcasting(255.255.255.255) I am able to transmit data to the network .but not to the destination address in which i am supposed to send.

Any suggestion on communication problem which we are facing.is there anything to configure in wiznet side .

I am new to networking kinds of concepts