Here is a guess. I looked at /etc/modprob.conf and my server has this line in it - alias eth0 3c59x. So, did a locate 3c59x to find what was being loaded. I did the same for pegasus. So, from that, it looks like you can add this the /etc/modprob.conf - alias eth2 pegasus. Then in /etc/sysconfig/network-scripts, create a file called ifcfg-eth2 and fill in these paramaters:
TYPE=Ethernet
DEVICE=eth0
USERCTL=no
ONBOOT=yes
PEERDNS=no
IPV6INIT=no
BOOTPROTO=none
IPADDR=x.x.x.x
NETMASK=x.x.x.x
NETWORK=x.x.x.x
BROADCAST=x.x.x.x
Reboot and see if it comes up. Modprobe.conf is templated so if the interface did come up, you can create the appropriate templates so that the settings will be preserved duing a reconfiguration reboot event.
Let us know if this did indeed work.
John