Yes, it is definitely possible as long as the rig controls have identical names. The only difference between the referenced nodes and the non-referenced ones is the namespace before the node name.
The goal is then to copy your controllers' animation and paste it to the same nodes but with a suffix before the name.
If you want to do it without plugins, you can use the Maya ATOM anim exporter. (Main menu/Maya/ATOM/export animation)
Select your controllers and export the animation in a file.
Now you can reference your rig, select the same controllers, open ATOM
Importer and select "string" as the "match method".
In the suffix area, write down your namespace (the suffix that your controllers' names god once referenced) including the semicolumn ":"
This way, you should be able to correctly paste the animation to the referenced rig.
There is also a nice plugin called Studiolibrary that you can get for free and use to copy and paste
animations in the most flexible way.
Cheers
Dino
