Contact list maintenance - repost

This is a job I need performed typically about once a week. I will give you a list of about 100-300 people who we invited to an event and a list of about 50-200 people who registered to attend the event. From those two lists we need to create a master list which shows everyone and indicates whether they were invited (not all registrants were invited), and what their registration status was ("general admission," "waitlist," "cancelled" etc.).