You need to do a money transfer or banker's draught. There are companies like Western Union who are specifically set up for this. You give them the money and the relevant bank details and they do the transfer for you. You'll have to pay conversion fees and what not, and extra P&P, but that's what you get for trading internationally.
If you've also got the problem of Germany stealing your lend-lease, first of all you have to explain to me how you managed to get enough figures to play World at War in the first place, cos the ones you get in the box are bloody useless. Then you wanna get Russia to hit back hard through the Baltic States, while you team up with the UK for a huge invasion into France. As long as Germany aren't dumping 20 infantry into Germany each turn, you're looking at an Allied win.
