Freezing a formula

Hi All, not sure if this is possible...

I have a formula that looks at certain dates. It matches those dates against another sheet and returns a number.

Is there a way of keeping that formula set after it's returned the figure?

For example, on the document I'm working off it's looking at a TODAY() formula and matching that against a list of dates. By tomorrow it will be looking at a different date and the figure returned will become an error value.

Any ideas...?