$5 Prepaid credit card

Hello.

I have a prepaid credit cards with $5 in it. I was wondering if there was someway "transfer" that amount to my iTunes-balance.

I have gift card at home that I would like to add to so the "amount" of money would grow, so I could buy a "better" amout of "premium currency" in-apps.

I have bothe a Swedish iTunes-account and an American iTunes-accont.

I would prefer if this was avalible to do for the Swedish iTunes, since I currentry have 150 SEK in a gift card, but only a $15 for my American.