How could I get my child back from her grand mother who left the country about 4 or 5yrs ago with out my permission?

My daughters grandmother took her to japan and has refused to let me speak to my daughter and I only gave her grandmother temperarily coustdy of her. She removed her from the US state of FL without my knowledge and took her over there so I was wondering if anyone could help me try to get her back and at what price?!