DLC content inside switch NSP iostore utoc mount

Hi I have the need to export ucas&utoc on an nsp of a dlc (I already have created the DLC package with ucas and utoc of chunk1)
I am trying to mount it but I dont see a correct way to do it
is there anyone that have experienced on mounting chunk1 at runtime and access it?

Many thanks!

Stefano Peranzoni