Excel 97 Question

[Paula & John <jhl3@xxxxxxxxx>]

I'm trying to link some data in Metastock (6.0) to Excel spreadsheets, so
that I can combine technical analysis number crunching with fundamental
data number-crunching (which data I get from my Zacks database).  I'm able
to update stock prices en masse--i.e. one complete set of data from
Metastock to Excel, adding the current day's data to the previous data--but
all I want to do, for now, is replace yesterday's price of a given stock
with today's price:  change the data in a single cell, in other words.  

I'm sure there is a simple way to do this, but my knowledge of Excel is
limited to pretty simple functions.  

Thanks for any help you can give.

Paula