How to install MikTeX packages outside of install directory?

Is it possible (and if so how) to configure MikTeX to install packages outside of the install directory of MikTeX itself?

For example, say I have a user-only (--shared=no) install of MikTeX to my home directory on the system partition, e.g. C:Users<name>AppdataLocalProgramsMikTeX.

However, I want packages installed to another drive (say, "H:"), both during setup and subsequent updates/additional package installs.

Is this possible, and if so how?

For context: MikTeX will be virtualised under App-V with its own virtual file system to which the user will not have write access. The user’s C: drive likewise is ephemeral because we are using non-persistent virtual machines. Users have a home directory on an intranet share, mapped to a local letter (say, "H:").

Apologies for the cross-post from SO but it occurred to me too late that tex.stackexchange is the more appropriate community. Will delete other post if required.