Format in Excel 2003
Excel offers you an ability to assign user-level permissions to different areas on a protected spreadsheet. You can specify which users can edit a particular range while the spreadsheet is protected. As an option, you can require a password to make changes.
One of Excel's best-kept secrets is its ability to copy and paste pictures of cells. You can copy a cell or range and then paste a picture of the cell or range on any worksheet or chart.
With Excel built-in tools you can easily work together on workbooks and monitor who, when and what changes made. E.g., track project status and tasks.