Chart.ProtectFormatting Property (Excel)
True if chart formatting cannot be modified by the user. Read/write Boolean.
A variable that represents a Chart object.
This property is not persisted when the file is saved. If you set this property to True and then reopen the file, it will no longer be set to True.
This example protects the formatting of embedded chart one on worksheet one.
Worksheets(1).ChartObjects(1).Chart.ProtectFormatting = True