You need to recomiple your Kernel with support for that particular soundcard.
I am not 100% certain how RedHat works, but I think you can simply drop to a command line, cd into /usr/src/linux, then:
This will show you the kernel configuration menu. Find the Sound section and make sure you mark the right sound card (make it as a module, so you can see if it is loaded later on).
From there, save your configuration and
make dep && make bzImage modules modules_install
and you should be good to go. There are lots of great guides to recompiling your kernel elsewhere, so refer to them for specific instructions about your distro, etc.