Migration from Old Web Server to MOSS07-hosted Web Site

Our existing web server is configured with two separate IP addresses. Let's
call them 192.168.1.2 and 192.168.1.3

Internal DNS host records exist for www.mydomain.com pointing to 192.168.1.2
and for www.myotherdomain.com pointing to 192.168.1.3

The external DNS host record for www.mydomain.com, let's say is xx.xxx.xx.3
and for www.myotherdomain.com is xx.xxx.xx.5.

Our firewall NAT’s external web requests for www.mydomain.com from
xx.xxx.xx.3 to 192.168.1.2 and for www.myotherdomain.com from xx.xxx.xx.5 to
192.168.1.3.

When the time comes for us to migrate the www.mydomain.com website from the
old to the new MOSS07 front end web server, it is pretty straightforward to
modify our 'https' service on our firewall so that the NAT’d address from
xx.xxx.xx.3 is changed to the IP address of the MOSS07 front end web server.
However, it is less clear to me how www.myotherdomain.com should be handled.

The Sharepoint consultants have advised us that access to the the content
which used to be accessible via the old web server via www.myotherdomain.com
will change under MOSS07 to be via a managed path below www.mydomain.com. But
some of our internal people still want to be able to access the new server
using the old domain name via their web browsers from the Internet
www.myotherdomain.com. Is it possible to have it both ways? That is, is it
possible to have the content of www.myotherdomain.com be redirected somehow
by using an external DNS name www.myotherdomain.com and have it re-directed
to a 'managed path' under www.mydomain.com on the MOSS07 front end web
server? How would the migration of the content be handled from the old to the
new web server in terms of our internal and external DNS records and the IP
addressing scheme of the new MOSS07 front end web server? Do we need to
create a 2nd IP address for the MOSS07 front end web server and continue to
maintain a separate and distinct DNS internal and DNS external zone and host
records for www.myotherdomain.com and just point the host records to
192.168.1.6? Or point to the 2nd IP address? Or are the two design goals
mutually incompatible?