Intercept Property
Returns or sets the point where the trendline crosses the value axis. Read/write Double.
Remarks
Setting this property sets the InterceptIsAuto property to False.
Example
This example sets trendline one to cross the value axis at 5. The example should be run on a 2-D column chart that contains a single series with a trendline.
myChart.SeriesCollection(1).Trendlines(1).Intercept = 5