Convert CDA to AAC

It is not possible to directly convert CD Audio Track Shortcuts to Advanced Audio Coding Files (.cda to .aac conversion), as CDA files do not contain any audio data. They are merely shortcuts referencing audio tracks on a CD.

You can, however, rip the CDA files off the audio CD and export it in AAC format. This can be done with a dedicated tool or (online) conversion utility, such as Switch Audio File Converter or fre:ac, which should allow you to rip off CDA audio from a CD and export it in AAC format.