How Do I auto-populate cells in a master workbook by referencing cells in other workbooks that have

I have a master workbook that I do not want anyone touching. I parsed the data from the master across 3 separate workbooks. Each of the 3 team members has one of these excel workbooks. When they make a call to a contact, they use a data validation list to choose from and mark one of the cells "CLOSED" or "OPEN". I want these statuses to auto-populate the master workbook. I am having difficulty finding a formula to use, given I am referencing cells with data validation formulas.