If any cdt to jpg conversion is possible, it would be export of CorelDRAW templates or some of its elements (.cdt) to JPEG format. It is likely that the only software that can reliably work with these templates is CorelDRAW itself, so it's not like you have many alternatives for this. But some tools claim to support CorelDRAW formats, so perhaps you can try them out as well, if you do not have access to the original software.
Updated: April 11, 2023