Solution to using numbered backreference followed by digit in lineinfile

example.yaml

---
- hosts: localhost
  tasks:
  - name: create file
    copy: src=./demo dest=/tmp/demo

  # not working as expected
  - name: update xxxx
    lineinfile:
      dest: /tmp/demo
      regexp: '^(.*)xxxx'
      line:   '\1{{ansible_date_time.year}}'
      backrefs: yes
      state: present

  - name: update yyyy
    lineinfile:
      dest: /tmp/demo
      regexp: '^(?P<group>.*)yyyy'
      line:   '\g<1>{{ansible_date_time.year}}'
      backrefs: yes
      state: present

  - name: update zzzz
    lineinfile:
      dest: /tmp/demo
      regexp: '^(?P<group>.*)zzzz'
      line:   '\g<group>{{ansible_date_time.year}}'
      backrefs: yes
      state: present