I can display the Polynomial equation by the following code, onething

unsatisfactory it returns a 2 order Polynomial equation by default. but

I need to get the 4 order Polynomial equation for further process.

Your earliest reply will be highly appreciated!

xlBook.ActiveChart.SeriesCollection(1).Trendlines.Add(Type:=xlPolynomial, Forward:=0, Backward:=0, DisplayEquation:=True).Select