No, you can't. 'Cordial' describes a relationship, an atmosphere or a manner: it cannot describe a person. Someone can greet you cordially or welcome you in a cordial way:this word refers to their greeting or their welcome, not to the person himself. You may occasionally come across an example such as "I met him at a party last year. He was cordial but ...". This refers to his manner towards you on that occasion: he acted in a cordial fashion. It is not a feature of his personality.