Create a big WhatsApp group

I am looking for someone to create a big WhatsApp group to promote an upcoming event. I already have an extensive list of contacts and my target demographic includes both youths (18-24 years) and adults (25-55 years). I am expecting more than 200 people to join the group. The successful Freelancer will need to be able to quickly and efficiently set up a large, active WhatsApp group. The Freelancer should also have a good understanding of the number of participants in the group and have experience in its associated privacy settings.