Enable Autofilter Functionality For A Protected Worksheet
By default, the AutoFilter functionality in Excel becomes unavailable when you protect part or all of a spreadsheet. If you use Microsoft Office Excel 2003 or Excel 2002, you can restore that functionality manually. If you use Excel 2000, you need to use a few lines of Microsoft Visual Basic for Applications (VBA) code. You use AutoFilter to quickly find and work with subsets of the information in a worksheet. The following paper provides more information about using the AutoFilter command.