Why do so many dispute the possibility that correctly locking/unlocking cells, and protecting the worksheets/workbook will give the desired result?
Is this a "control issue"? Do people resent the concept that other's activities may need to be restricted?
Seriously folks, if your request sounds like a situation where the user's interaction must be restricted, please READ THE HELP FILES regarding locking/unlocking cells, and protecting worksheets/workbooks.
It is true that the most recent versions of Excel allow greater control over what is being restricted. So, maybe the simple answer is to get a copy of Excel XP 2002?