There is nothing available. So far what has been established is that the 24" ACD apparently doesn't support DisplayPort's DVI pass-through which means that a simple dongle from DVI->MDP will not be sufficient to drive the monitor.
Either Apple would have to change this or launch a new version of that screen with DVI input to be able to sell people like you a new ACD. If they refuse, you will have to buy your 24" screen some place else.