Is there any possibility to export expressions from CC3 to FBX as blendshapes?

You probably need to export from iclone creating an one-frame animation.

I guess you wanna so custom blendshapes  right? 

I need (and all who are developing characters for game engines need too, I think) to have additional ready-to-use blendshapes as Agree, Fear and so on, embedded into a character along with the already existing elementary face morphs. Using one-frame-animations is a legacy way from XX cent, just if necessary expression exists as Motion+ file.