[Samba] Allow users to delete from read-only share?

[Joe Konecny]

When using Netware I had two directories set up as follows...

1. /data/cad/current
2. /data/cad/hold

I had three groups that controlled access to these directories.

Group A had read-only access to 1.
Group B had read-only and delete access on 1 and read-write on 2.
Group C had read-write on both 1 and 2.

Group A was typically shop floor employees who needed to
view cad drawings.  The reason for group B was so that an
engineer could take a cad drawing file and remove it from 1.
and place it in 2. so that no one could access it while it
was being modified.  When the modifications were complete
and approved a user from group C could put it back.

I cannot figure out any way to do this with Samba.  Any tips?