bjw -

The usual solution is to add three more data series to the chart, each with
the weeks of interest, add a trendline to each of the new data series, and
format each of the new data series to not show markers or lines.

If you have difficulty selecting a new data series, select any object on the
chart, and use the arrow keys to make the selection.

- Mike
http://www.mikemiddleton.com

"bjw" wrote in message
...
I have a line graph with 3 lines, 1 for each year 2004-2006. X values are
the weeks in the year and y values are the units of inventory. I want to
add
a linear trendline for each of the 3 years but only starting from week 29
or
30 (where the line started to go up again). Is that possible?