You cannot configure the Cap Type and Join Type properties for line styles in a chart by using Visual Basic Applications (VBA) code in Microsoft Excel. You can only configure these properties by using the settings in Excel.
Note Line styles include borders, series and trend lines, marker lines, and any other object that has the Cap Type property.
The Cap Type and Join Type properties do not have corresponding object model properties that you can use in VBA code. Additionally, by default, the Cap Type and Join Type properties are set to Round.