URGENT: PLEASE HELP

I would like to know of a cell format setting, a formula, VB program, or any
other method to automatically resize the font size if the value entered is
too large and results in the display of the following: "####..." It would be
ideal if the font would downsize so that numbers could be displayed.

The cells display numbers, size 12 font, tahoma. Numbers up to 999.99
diplay, 1,000.00 (+) displays "###". Workbook was originally designed to
accomodate larger numbers using size 10 font, but other parties decided much
later in the game that they wanted larger text.

INFO: My workbook has many similar worksheets that are intended to be
changed regularly. Each workesheet has hundreds of cells that are
referenceing another worksheet's data or some other source. When a value
entered in the "referenced cell(s)" is too large, several worksheets could
have cells displaying the aformentioned error. My deadline is near and the
workbook has grown too large to make the affected cells larger (ex. by
merging more cells) to accomodate more text and/or to review each worksheet
for any affected cell.