CDR/DirectCD API

Just like Obi-Wan Kenobi, you're my only hope!
We're using Adaptec's Direct-CD with some CD-RW units, and we'd like to be able to close "full" (ie only around 15Mb free) CD-Rs to ISO9660 CDs. We can do this thru menu options, but not from a program, which is just *asking* for trouble. The final system is going to be used in a retail environment, so we need it bomb/bullet/fire/nuke proof, and relying on someone using right-click in explorer doesn't sound cool to us.

Can anyone shed any light on how to do this programmatically? Our environment is NT4sp4,VS6sp3.

Tx in advance