Plotting multiple data streams on one chart with a common starting point

["jbclem1" <jbclem1@xxxxxxxxxxx>]

A mutual funds database and charting program, Fasttrack, has a chart called Total Return where they
show multiple data streams( indices and/or mutual funds) starting from a common point at the left
side of the chart and then each following it's own path towards the right.  It's an easy way to
compare the data streams as they progress in time.  I'm trying to figure out how to do this in
TS2000i.

Here's the description from the Fasttrack manual.  It seems simple but I haven't gotten it right
yet.

"The chart is a series of percentage change points so that the fund and the index can be plotted on
the same chart and meaningfully compared. "  "Each point on the chart is plotted using the formula:

" CurrentNAV-PreviousNAV)/First NAV "  or my version  " (Close-Close[1])/FirstClose "

Substituting the Close for the NAV(Net Asset Value), I'm stumped by the "First NAV" (or FirstClose)
term.

Here's a link to a chart with a good example of this kind of chart:
http://www.fasttrack.net/franklin.asp .

I'd appreciate any suggestions.

John