You normally can't change things in /proc, its a psuedo filesystem that is created upon bootup.. it actually goes away when you turn the computer off, etc, and if you change it now, upon next bootup, its most likely going to revert back.
Why don't you create symlinks instead to the proper /dev devices.. ??
ln -s /dev/hdc /mnt/cdrom1
ln -s /dev/hdd /mnt/cdrom2
Or something along those lines..