I used this strategy to pay off part of a high interest student loan with a 0% balance transfer offer.
What I did was send the balance transfer amount to a different credit card (let's call it credit card #2). Then, once that had been credited to credit card #2, I requested a reimbursement of the balance on credit card #2. They cut me a check, I deposited it into my checking account, and then paid my student loan.
I then paid off the balance on the 0% balance transfer card before the critical date, so that I wouldn't be charged interest. It worked out great- I saved about a year's worth of interest with this strategy.
The credit card companies did not check to make sure credit card #2 had a balance (it didn't) before transferring the money, or ask anything when I requested reimbursement from credit card #2. I don't remember whether this is card specific or if you can do this with any card, but I do remember researching the strategy on Fatwallet, so searching around there will probably answer that question.
Good luck!