Please help :S Reorder eth numbers?

Hi all,

This is regarding Gentoo linux with the latest kernel.

Sorry have a horrible problem im stuggling to find information about.
I have changed a network card on a firewall computer. Using ethtool it
seems to find the new network card at eth4. The old one was eth2, is
there a way I can remap eth4 to replace eth2, as eth2 is no longer in
the system, and it would save a lot of time setting up squid, iptables
etc again?

Also can anyone confirm if ethtool sees the network card, then the
driver must be loaded in the kernel? I cannot currently see this
network card using ifconfig.

Thanks in advance for any help

David