Can systems on the sgsadmin ping the IP Address for parentsintranet.sale.com?
If so, all we need to do is fix Name Resolution. You have a few choices there, all of them must be done from the DNS servers for the sgsadmin.com domain:
1. Add a Conditional Forwarder directing queries for parentsintranet.sale.com to the appropriate server.
2. Add a Secondary Zone for sale.com and transfer the data from the servers responsible for that domain.
3. Add a Primary Zone called parentsintranet.sale.com, add a Host (A) Record with a blank name pointing to the IP for the server.
I hope that makes some kind of sense to you!
Chris