looking for advice ,when removing rear caliper my brake pipe broke close to where it screws in to caliper.where do i get a new pipe from and where does it join?? do i need any special tools

I have my own Sykes -Pickavant flaring tool but most motor factor shops will make up a brake pipe for you. They just need to know the length and what unions are on the ends. Obviously you'll need to bleed the brakes after fitting it. Ask for Kunifer (cupro nickel) pipe as it is corrosion resistant and the best stuff to use.