Need help running cd images on the dosbox core Retroarch 1.5.0

I have a lot of old DOS cd games and for convenience I would like to run them through Retroarch instead of D-fend Reloaded. That way I can use one program for all my retro console and old PC games. can some body please give me a simple step-by-step guide to running DOSbox through Retroarch including how to mount cd images and add my gamrs to a library for quick launch. Any help with this would be greatly appreciated.