Here is my understanding: CC2 can only import modified CC characters (which will get a key when being exported).
For non-CC (e.g. DAZ) characters you need 3DXchange, which will then convert that character into a non-standard iClone character. This character can be used in iClone, but it is not compatible with Character Creator.
CC3 Pipeline will have the option of directly importing and converting characters into proper CC characters, However, I believe this is restricted to DAZ characters of various generations.