Internal mixing problem about CuMix in Cubase

[nanairo]

Hi, guys.
I'm a 828mk3 user who runing the Cubase host system within it.
I have a question about CuMix function for interal mixing in Cubase.
Could I route the studio output bus(total mix signle)of Cubase,
thru 828mk3 output and then back into a CuMix input track internally,
(I mean without any substance cable like line I/O or S/PDIF and ADAT)
and use this input as a new audio input into a new audio track for mastering?

I have used the TotalMix function of RME FF800 to achieve this needs before,
but have no idea does CuMix function of 828mk3 could achieve it or not.
Does anyone have experience to teach me how ? or tell me the possibility?

Thanks a lot!!

Presto

[XYZ]

I don't think this is done easily, or maybe at all (I could not figure out how to do it); however, I have this same basic need and, since I don't use S/PDIF and it remains pure digital, I just routed the main mix out to my mains AND SPDIF, with a short rca patch, and then the spdif input can be routed anywhere.