How do you protect data in a cell and only allow authorised staff to view

You can protect entire workbooks by going to tools>>protection>>protect workbooks. You can put a password in the sheet and only give the password to the staff you want. But you cannot protect a particular cell in the worksheet on its own and not let anyone see it. What you could try is hiding the column where the cell is. Then protect the worksheet with a password. Staff who knew the password would be able to take the protection off and then unhide the cells. Staff who didnt know the password cant take off the protection and then unhide the column.