If by “virtual” you mean remote or long distance, most professional, high-level translation companies in China use the services of foreign subject matter experts (SMEs) who are not in China, especially when it comes to copy editing doctoral dissertations and academic papers headed for Western journals. One such translation company that I used to work for is
New Bridge Translation in Guangzhou. You will need a minimum of a master’s degree to be competitive for this type of freelance copy editing position. This is the only type of copy editing work that pays enough to make it worthwhile.
Companies that cater to local businesses and municipal governments translating documents like brochures and menus will typically hire local foreign English teachers recommended to them by mutual acquaintances or their schools' foreign affairs officers at very low fees or in exchange for gifts, usually in the form of a dinner or decent carton of cigarettes. These companies do not have enough of a budget (or the right clientele) to justify hiring remote foreign matter experts or professional foreign copy editors.
To find translation companies that may need foreign copy editors, simply conduct a search on “Chinese to English translation companies.”
Best of luck.