Thanks for all the replys.

Semi-automating the process of writing via the XP shell built-in can be done with VB, but the object ain't that easy to get hold of so I don't think I'll bother with the pain of trying to get it to work in KiXtart.

For those that are interested, here is an example of how to do it in VB:
http://www.vbaccelerator.com/home/VB/Code/Libraries/Writing_CDs/Simple_CD_Burn/article.asp

I've handed the problem back to the dev staff, as their app is VB based so they should be able to integrate it.

I'll have a look a the free tool links as well, once I get hold of a working cd-writer.