In the mac address authentication profile, you can specify a format. Part of the format is Delimiter, or none, colon or dash. For one SSID make the mac authentication profile have no delimeter, so that the mac addreses will have to format AABBCCDDEEFF. The other SSID will have a mac authentication profile that has a delimeter of Colon, so you will enter those mac addresses of AA:BB:CC:DD:EE:FF.
The end result is tht devices will authenticate with a different format, depending on the SSID that they connect to, and you have to enter them into the internal database differently, as a result.