By Rosaleen Fenton So far, King Charles has never needed to call on a fellow royal to stand in for him when he is abroad or undergoing any medical treatment, but all that might be about to change. Sixteen months into his reign, the royal may need someone to deputise for him as he undergoes medical treatment for an enlarged prostate. Buckingham Palace has announced today that The King is to be treated in hospital next week. There are currently seven counsellors of state – members of the royal family who can deputise for the monarch if he is abroad or unwell. This includes the Duke of Sussex, wh…