The effect of damping upon the spectrum values

As you clarified in "STAAD.Pro Response Spectrum [FAQ]", if seismic effect combination method is SRSS, the effect of damping is built into the spectrum values. How about CQC method? How to reflect the effect of damping upon the spectrum values that is being input?

Furthermore, if CDAMP is specified, as we know, each mode may have the unique damping value, how to deal with this case?