that should be the BT keyboard's address. you can get it's mac via "hcitool scan" (as described by JoHnY here).
yes it does those "xx"es are just placeholders. every mac address has the same length, twelve bytes. (six pairs)
btw, all those commands were single commands split by a backslash ( \ ). using a backslash, you can write a multiline command, by "masking" the linebreak with it. JoHnY did the same in his post (manually connecting the BT keyboard), he just wrote every command in one line.