Ken
not tried this but it seems you used LINEST function on the data to get
what you need
I found the MS help a bit un-helpful but this link may help
http://www.stfx.ca/people/bliengme/E...Polynomial.htm
also much more with a Google search

you should be aware that the accuracy of LINEST does not always match that
of the Excel curve fitting. Again see the google search for more detail.

hth RES