Depends upon what you mean by a complex animation.
For each actor you can save motion clips for custom motions and facial expressions for reuse.
You can save a group of props as a scene which can be loaded in other projects (Note that only one scene can be loaded at a time in a project).
You can group multiple props into a single prop for use in other animations.
You can save the current project as a different project, load that project copy and just modify those elements that need it.
Jeff
Get my Plugin Manager and TaskNotes plugins for iClone.
Check out EZColors and Other products for CTA/CA. EZColors: the easy way to change Render Styled (RS) colors!
See my CTA Tutorials on the YouTube channel CTAStepByStep