virtualbox.org

I know it is not possible for this to work in a real network.
But it is not that bandwidth demanding in the same machine
to run a network drive as a physical drive in an xp guest.

If I directly mount a network drive to xp, it is not possible
to subst or net use it and make it appear like a physical one.

But can virtualbox itself help me to do this trick.
I just enjoy to have the xp guest as if it is a real system.

Thanks
Jack

No, VirtualBox can't do that. VirtualBox virtual drives always require an underlying image file to receive sectors. A network drive doesn't have anything like that. E.g. how would you go about formatting and partitioning a network drive with the EXTx filesystem?

A network drive is really an API, not a storage medium. The illusion is barely skin deep.