Hi @sireneweb
Yes. This is quite easy and all you need to do is add a WYSIWYG field, then in your functions.php file, use the acf/update_value filter to hook into the save.
In the filter, you can get the value and use it to update the post’s the_content value. Have a look at the wp_update_post function on the WP codex site.
Good luck!
