Excel 2000

Dear All

I have a spreadsheet which is performs as a media planning chart. One Row
per day with different Magazines in each column. Each non-blank cell
contains the product name that has been advertised in the Magazine (columns)
that appears on the row 1 on the Date (rows) that appears in column A.

I would like to add functionality to this sheet by being able to hover or
click on a particular cell and for certain values to appear in a Comment
Box, Validation Message or Text Box.

These values would normally be based on a vlookup formula.

I tried putting a formula into a Text Box. This worked for me when I put a
simple cell reference formula e.g. =f4 but did not work with a formula like
=vlookup(f4,testrange,2,false). Any clues why this does not work.

From viewing past postings I like the idea of using the Validation Input
Message but I am not sure how this works.

Ideally I would like the abilty to have several different vlookup formulas
bringing back information into the Comment,Text or Validation box. i.e.
Sales, Cost of advert, Profitability. This information would be in columns
2,3 and 4 of a table in a different sheet.

Can anybody suggest any solutions to this problem.

Regards

George