Opening a workbook as a read-only should not, in itself, cause the user to be unable to filter. Not sure if this is available in Excel 2002, but you shouldn't need a macro
When saving your "master workbook" use Save As and then click on the Tools dropdown of that window> General Options and check "Read Only recommended" Then the user will be prompted upon opening the file if they want to open it as a read only.
Hope that helps.
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