AFAIK the s97s has 5.1 analogue output, which means it cannot possibly deliver decoded sound for more than 5+1 channels.
But dont worry. 6.1 audio (i.e. DTS-ES and Dolby Digital EX) is encoded in such a way that non-compatible gear reads it as ordinary DTS or DD. This means you just need put it into an ES/EX compatible receiver, using one of the digital interfaces. The receiver will decode it correctly as 6.1.
7.1 works in a similar way. Actually I think it is just a matter of splitting the sole rear channel into two speakers.