Perhaps conditional formatting would be a better option <g>
This example assumes you want to conditionally format
an adjacent cell if a certain trigger condition
is activated in another "target" cell
Assume you want to conditionally format B1 to display
the font in red & bolded, if the number in A1 exceeds 10
(A1 will be the "target" cell here)
In B1, you might typed have a text-phrase
relevant to the number in A1, e.g.: "Alert!"
Try this:
Select B1
Click Format > Conditional Formatting
Under Condition 1, make the settings:
Formula Is| =$A$1>10
Click Format button > Font tab > red/bold > OK
Click OK at the main dialog
The text-phrase in B1 will then appear
with font in red & bolded
whenever the trigger condition is activated
i.e. A1 > 10
(Test this out by inputting some numbers in A1)