Protect a cell for entry authentication

[Evilbob]

I'm setting up a system of spreadsheets for staff payroll timesheets and I need some way for each entry to be authenticated by a supervisor. Each staff logs in to the server and can enter their shift details on their timesheet. I'd like to have an extra column beside each shift entry that can only be edited by entering a password. The standard excel protection is not enough, as staff would need to re-protect the cell after each entry, and a lot of them will not remember to do that and this would also lead to entries being re-protected with an incorrect password.

Is their any way to protect a cell that would ask for a password, and allow a one-time edit of a cell and then protect the cell again automatically? Such a process might consult a list of passwords and enter a value to the cell based on which password was entered.

[:) Sixthsense :)]

Better go for Ms-Access