Unless you were in the business of forex trading, there is no place to report this loss ( or gain ). Sorry.
If my memory serves me right, IRS Reg 867 deals with the effects of currency exchange fluctuation/ drift for US businesses with foreign branches/ units of operation and even there the repatriated amounts are devoid of currency effects ( i.e. losses are realized but not recognized). Sorry -- that is one of the risks of dealing with a currency other than US functional currency when filing US returns
