Explain a little more about your needs, please.

By definition a cell with no data imported into it has no value.  It is
Empty.  You cannot control Excel's default cell contents, as when a new sheet
is entered.

There are things that can be done via macros, and some things that can be
done with worksheet functions, such as putting this formula in a cell (it
could go into any cell except B1 itself:
=IF(B1=9,"B1 is 9","B1 is not 9")
you can substitute other phrases for what is in that example, or even
values, as:
=IF(B1=9,14,"")
which would display 14 when cell B1 has 9 in it, and not display anything
when B1 does not have 9 in it.  You can even use the contents of other cells
as either of the parameters, like this:
=IF(B1=9, H4, J12)
so when B1=9, the cell with this formula in it would display the contents of
H4 otherwise it would display the contents of J12.

You can mix and match text, values and cell references within the IF
statement.