rgb to cmyk conversion?

[sakurama]

I am trying to understand, if there is a possibility to convert rgb to cmyk in Xnconvert.

There is a possibility to change the ICC profiles but the necessary (input and output) profiles are missing in my version and I can not seem to find the apropriate rgb and cmyk profiles in the web.
What went wrong?
Thanks for getting back to me
Andreas

[xnview]

sorry but not possible