Bemvindo ao forum. Well, let me see if I've understood your question. Do you need a boot disk to install RedHat 9.0? Because that's not necessary. You can simply change the boot order into your computer bios to boot from the CD-rom. Then you place RedHat Disk 1 at the drive and it should start the installing process.
BUT, if you mean you need a boot disk to actually start a previous installed RedHat (for any reasons, such as lilo/grub problems or others) then you would like to check this link:
Boa sorte meu amigo.