What is the Virginia Law regarding out-of-state Court Orders?

I live in CA. I was the legal guardian for my two young grandchildren for almost 4 years..until March, when they were returned to their father (against my better judgment), and they all now live in VA. The CA Superior Court judge ordered minimum twice monthly visitations with my grandchildren who now live in VA. Must I register this court order with VA in order to see or talk to my grandchildren? The VA court clerk doesn't know.