Effectively the transfer of money from Credit card to your account will be treated as a cash advance, with interest normally accruing from the date of the advance, plus a transaction fee.
But nevertheless you can effectively use your credit card to extend your working capital, once you are disciplined enough to pay off
In the scenario you outlined, you can effectlively get the same result by leaving payment of bill to the last possible moment without accruing interest charges. This way you effectively have use of the item for 56 days without paying for it, but that is reasonably standard practice for many people who use their CC's wisely