In order to maintain overseas program activity for the Department of Commerce provided for each fiscal year at the appropriated program levels, the Secretary may establish Buying Power Maintenance accounts for the International Trade Administration, the Export Administration, and the United States Travel and Tourism Administration. There are authorized to be appropriated for such accounts such sums as may be necessary to offset adverse fluctuations in foreign currency exchange rates, or unbudgeted overseas wage and price changes. To eliminate substantial gains to the approved levels of overseas operations, the Secretary shall transfer to a Buying Power Maintenance account such amounts determined to be excessive to the needs of the approved level of overseas operations because of fluctuations in foreign currency exchange rates or changes in unbudgeted overseas wages and prices, including unobligated balances associated with the overseas program. To offset adverse fluctuations in foreign currency exchange rates or unbudgeted overseas wage and price changes, the Secretary may transfer from a Buying Power Maintenance account such amounts determined to be necessary to maintain the approved level of overseas operations under an appropriation account. Funds transferred by the Secretary to or from a Buying Power Maintenance account to another account shall be merged with and be available for the same purpose, and for the same time period, as the funds in the account into which transferred. Any restriction contained in an appropriation Act or other provision of law limiting the amounts available for the Department of Commerce that may be obligated or expended shall be deemed to be adjusted to the extent necessary to offset the net effect of fluctuations in foreign currency exchange rates or unbudgeted overseas wage and price changes in order to maintain approved levels.