Online Showing Card

We are a real estate broker with 40+ offices in Michigan. We are using a ms access database system to track home showings. I've attached this sample ms access file. We are looking to convert this to an online system. We need one person (or more) to have full admin rights. We also want each office to only have office rights (so they only see their agent showing data) We want this online system to do at least everyhing that the ms access system does and open to more ideas to add to funtionalty.