Well, sticking it in should work in Mandrake (it uses a special utility called supermount).
It should then be in the /mnt directory, usually under /mnt/cdrom or /mnt/cd.
If that doesnt work, you have to mount it manually, like this:
su -c "mount /mnt/cdrom"
Replace /mnt/cdrom with the proper directory (look in /mnt).