Doddington is Canon Black's curate, but his job description seems to extend beyond being the Canon's secretary to be being his general dogsbody. Whenever we see him he is either performing secret deeds for the Canon, or off to the Church Social Club.
Doddington appears somewhat weak-willed, which is probably why Black hired him in the first place. He's often the butt of Black's dismissive put-downs.
The pilot of Strange marked Samuel Barnett's television debut. He has since played Brian Byrne in The Inspector Lynley Mysteries episode Well Schooled in Murder.