I'm not sure what you are trying to achieve.
cfitz has already told you how to use InCD for storing files on your CD-RW discs as if they were big floppies. For instance, if you have an MP3 file on your hard disk, you can use Explorer to copy it to an InCD formatted CD-RW disc, either for backup or because you want to use the disc in your player or on another computer.
In other words, InCD only handles copying files, and not conversion between different file formats. If you don't have an MP3 file, either download it, or if you have a music file in another format, use your favorite software to convert it to MP3; in both cases save the MP3 file to your hard disk first before copying it to an InCD disc.
Apparently you have misread the complaints about InCD. In most posts, "I can't get InCD to work" means that InCD is not working properly; in your case, it seems to mean that you don't know how to use it.