NX4 replication to remote NX4 over the WAN with NAT

Hello,

I'm in the process of trying to  set up a replication of my production NX4 to a remote NX4 at a colo for  disaster recovery.  The two sites are separated by the internet and use  two firewall/routers to communicate.  Since my DR is at a colo I use  network address translation to grant access to resources behind the  firewall/routers.  In my production environment my NX4 has all private  IP addresses that use the 10.X.X.X format.  I would like to setup my DR  site to use the same 10.X.X.X format.  I have a number of servers  linking to the NX4 in my production environment via the iSCSI LUN.  In  addition I have all my servers as virtual machines with XEN Server  stored in a virtual storage repository which is a iSCSI LUN on the NX4.   My goal is to replicate all my NX4 production data to a colo DR site  with a matching NX4.  I would like maintain all the private IP address  structure between the production and the DR to be the same so all the  server configurations can be the same.  That way I can spin up the VMs  with minminal changes and reduce the time it takes to recover from a  disaster.

For Example:
Production  NX4
System	Internal	External
CS	10.0.20.10	123.123.123.10
Data  Mover Interface	10.0.30.13	123.123.123.13
SPA	10.0.20.11	123.123.123.11
SPB	10.0.20.12	123.123.123.12

DR NX4
System	Internal	External
CS	10.0.20.10	321.321.321.10
Data  Mover Interface	10.0.30.13	321.321.321.13
SPA	10.0.20.11	321.321.321.11
SPB	10.0.20.12	321.321.321.12

The issue  I’m having is setting up the data mover interconnects.  I was able to  specify the Celerra network servers by their external IP address.  My  production NX4 knows about the DR NX4 CS (321.321.321.10) and my DR NX4  knows about the production NX4 CS (123.123.123.10).  They are able to  communicate just fine.  When I go to configure the data mover  interconnects between the sites the system only allows me to select  (check mark) the interfaces of the NX4, which are the private IP address  (10.0.30.13).  It does not allow me the option to specify the external  IP addresses (Production 123.123.123.13 and DR 321.321.321.13).

How do I configure the data mover  interconnects to use the external IP addresses rather than the internal  private IP addresses?