if you can use a program called Notepad++ (Not to be confused with just regular notepad), you can open up a file that contains all of your cats for that clan and their information such as names as well as various other data I haven't yet figured out the purpose of (most of them are numbers I can't decipher so far). Assuming it isn't corrupted, I haven't tried this out, but in theory you should be able to start a new clan, save it, open the new clan's cat file in N++, and copy+paste cats over from the old cat file. Save the changes you have made, and open that clan in the game; if it works, I imagine there will now be your favorite imported cats from the previous save file.
I would make a backup of the newer clan just in case, though, as this could potentially corrupt or kill that save. I can't guarantee this will work, but I'm just thinking based on what little I do know.