Older .comicdoc files from the first version of Comic Life are still supported in the latest version of the program and can be re-saved to the newer .cl3arc files, which is what comicdoc to cl2arc conversion represents. It is unlikely that other software is capable of working with Comic Life file types, which makes the prospect of such conversion in 3rd party software somewhat limited.
Open COMICDOC file Open CL2ARC file