Generate Custom token for Confirmable devise

I am using devise:confirmable, and want to use custom token, as I need to append some data in the confirmation token itself. How can it be configured ?

User Model :

class User < ActiveRecord::Base
  # Include default devise modules. Others available are:
  # :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable,
         :confirmable, :password_archivable

Devise uses before create callback to generate token.

before_create :generate_confirmation_token, if: :confirmation_required?

You can override the generate_confirmation_token method from devise in your User model.

Bellow is default behavior of the method.

    # Generates a new random token for confirmation, and stores
    # the time this token is being generated in confirmation_sent_at
    def generate_confirmation_token
      if self.confirmation_token && !confirmation_period_expired?
        @raw_confirmation_token = self.confirmation_token
      else
        self.confirmation_token = @raw_confirmation_token = Devise.friendly_token
        self.confirmation_sent_at = Time.now.utc
      end
    end

Check this module for more info.