Chart.SetDefaultChart (Excel)

Specifies the name of the chart template that Microsoft Excel uses when creating new charts.

SetDefaultChart (Name)

Name: Specifies the name of the default chart template that will be used when creating new charts. This name can be a string naming a chart in the gallery for a user-defined template, or it can be a special constant xlBuiltIn (XlChartGallery) to specify a built-in chart template.

Dim strName As String: strName = 
ActiveChart.SetDefaultChart Name:=strName