How to convert .mp4 videos to .cpa format.
Converting MPEG-4 Videos directly to Adobe Premiere Conformed Audio Format (.mp4 to .cpa conversion) should be possible and straightforward, even though your options are limited.
It appears that your only option is using Adobe Premiere Pro itself, which should be capable of converting .mp4 to .cpa.
Set of professional software tools for graphic design, video editing and web development