The CCJ will be to pay a specific amount - either immediately, or by instalments. If the latter, and the instalments will go on for a long time, the creditor may be willing to accept a one off payment as an f & f settlement, but they may also well question how you can provide such a sum now when you couldn't/didn't offer it on the Court forms.
In any case, it is a matter for negotiation with the creditor and they do not have to accept anything less than full payment. Even if they do accept an f & f settlement the CCJ will stay on your CRA records for 6 years, probably marked as satisfied in part.