binding TCP for FTP/SSL to a specific interface

Is there a way to bind an interface to a specific NIC/IP address to be
used for routing to an external IP (or DNS name preferably but I'm pretty
sure the domain name isn't possible but I've been wrong before). We have
a situation with IPLs, etc "changing which NIC interface being used for a
FTP/SSL connection to an external vendor. This causes many headaches
(especially for the Firewall admin) since the firewall can't set up rules
for more than one internal IP address to send traffic via the SSL
connection. If this can be done it would definitely lighten the burden
for me & the admin. I know there has to be a way but I'm not a sys admin
type but am being forced to wear that hat anyway...


Thanks,
Tommy Holden