in reply to How to convert MAC address to IP address ?
Although it might be clear, I think it should be stated for those who do not know: the MAC address of a network card is relatively fixed by the hardware (disregarding spoofing and such), whereas an IP address can vary greatly, based on the network, DHCP, and other factors. Thus, there is no way to simply convert from a MAC address to an IP address with no further information.
But of course, you probably have more information. In that case, see the referenced nodes in the above replies.