Using Win XP with Office 2007;

I would like to test the contents of a cell to determine if it contains a
numeric constant (i.e. a number, but not a date, or formula).

For example, you would use IsDate to test for a date; is there an equivalent
for a numeric constant?

1) Could an example function be posted that returns true if the current cell
contains a numeric constant?

Also, is there a type for a formula?

2) If so, could an example function be posted that returns true if the
current cell contains a formula?

3) A formula that evaluates to a number?

Thanks in advance!