In order to mount your ISO you will need to add the ISO to your box, create the directory then mount the file,

root@host:~$ mkdir /mnt/iso
root@host:~$ mount -o loop -t iso9660 MYCD.iso /mnt/iso 

use the following command to confirm that you have mounted it correctly,

root@host:~$ df -kh

You should see,

Filesystem           Size  Used Avail Use% Mounted on
MYCD.iso             654M  654M     0 100% /mnt/iso

To unmount your image run the following,

root@host:~$ umount /mnt/isoimage