You will need to re-compile the Linux kernel in SCSI support, since the USB mass storage driver (appartently) just masquerades a USB device as standard SCSI.
Since the mass storage driver presents the USB device as a SCSI device, you need to turn on SCSI support, which is under SCSI support in the configuration script. You should also turn on subordinate options as appropriate to your mass storage device - usually one or more of SCSI disk support, SCSI tape support, SCSI CD-ROM (this would be you) support and SCSI generic support.
Then, after compiling SCSI support in, you make a mount point (just mkdir /mnt/cdrw or some such), and then put a mount command into /etc/fstab:
/dev/scd0 /mnt/cdrw iso9660 ro,noauto,user 0 0
Note that the actual device (/dev/scd0) may be different for you; my (SCSI)
CD-RW shows up as /dev/sr0.
You should then just be able to "mount /cdrw" and see the CD disk in there.