On May 13, the Department of State published a final rule that will allow third parties like attorneys of record to attend certain visa appointments. Read more here: https://travel.state.gov/content/travel/en/legal/travel-legal-considerations/internl-judicial-asst/Retaining-Foreign-Attorney/Foreign-Attorneys.html
NOTE: U.S. embassies and consulates overseas maintain lists of local attorneys who have expressed a willingness to serve U.S. citizen clients. But the lawyers listed are not US government endorsed or recommended and certain is not a guarantee of the quality of services provided. Typically, a client should use a trusted attorney practicing U.S. immigration law who may be located anywhere in the United States or the world and allow them to determine how your case will be run at the U.S. Consulate and whether local counsel will be needed. Most often, local counsel is not needed.