Okla. Stat. tit. 12, § 12-729.6: Determining amount to be paid in foreign money

A. If an amount contracted to be paid in a foreign money is

measured by a specified amount of a different money, the amount to

be paid is determined on the conversion date.

B. If an amount contracted to be paid in a foreign money is to

be measured by a different money at the rate of exchange prevailing

on a date before default, that rate of exchange applies only to

payments made within a reasonable time after default, not exceeding

thirty (30) days. Thereafter, conversion is made at the bank-

offered spot rate on the conversion date.

C. A monetary claim is neither usurious nor unconscionable

because the agreement on which it is based provides that the amount

of the debtor's obligation to be paid in the debtor's money, when

received by the creditor, must equal a specified amount of the

foreign money of the country of the creditor. If, because of

unexcused delay in payment of a judgment or award, the amount

received by the creditor does not equal the amount of the foreign

money specified in the agreement, the court or arbitrator shall

amend the judgment or award accordingly.