Modify copyright

I do not think it’s in the style.css

/*
Theme Name: Enfold
Description: <strong>A superflexible and responsive Business Theme by Kriesi</strong> - <br/> Update notifications available on twitter, facebook and via newsletter:<br/> <a href='http://twitter.com/kriesi'>Follow me on twitter</a><br/> - <a href='http://www.facebook.com/pages/Kriesi/333648177216'>Join the Facebook Group</a> - <a href='http://kriesi.at/newsletter'>Subscribe to our Newsletter</a>
Version: 3.5.3
Author: Kriesi
Author URI: http://kriesi.at
License: Themeforest Split Licence
License URI: -
Theme URI: kriesi.at/themes/enfold/
*/

/*
* PLEASE DO NOT EDIT THIS FILE!
* 
* This file is only in your themefolder for WordPress to recognize basic theme data like name and version
* CSS Rules in this file will not be used by the theme. 
* Instead use the custom.css file that is located in your themes /css/ folder to add your styles. 
* You can copy a style rule from any of your css files and paste it in custom.css and
* it will override the original style. If you just want to add small css snippets you might also
* want to consider to add it to the designated CSS option field in your themes backend at: Theme Options->General Styling
*/

<span class='copyright'>powered by mydomain.com</span>

this solution does not work because it remove any copyright that is created automatically. And function to add its copyright (in theme option) no longer works either.

I use the child theme but I do not see where I can make this change in style.css

/*
Theme Name: Enfold Child
Description: A <a href='http://codex.wordpress.org/Child_Themes'>Child Theme</a> for the Enfold WordPress Theme. If you plan to do a lot of file modifications we recommend to use this Theme instead of the original Theme. Updating wil be much easier then.
Version: 1.0
Author: Kriesi
Author URI: http://kriesi.at
Template: enfold
*/

/*Add your own styles here:*/

And I have no footer.php in the child theme folder.

Sorry I’m not an expert ;)
In addition I use wordpress for 2 weeks before I was using joomla.

ok renaming works but this removes the changes I made.
But cons I do not see where change the url and where change “WordPress Theme by Kriesi”
I do not want to use the nolink. I want this feature to be reserved for a possible future customer.

No it does not. this removes everything except the automatic copyright.
This is not what I want.

I do not see how this “<?php echo $copyright; ?>” could change this: “WordPress Theme by Kriesi”
and change the url

We must change the contents of this: $kriesi_at_backlink

And ideally I need to delete the name of the theme because I do not need and this complicates the change.

Obviously it is composed in part 3.

The theme name in the css
the phrase “WordPress Theme by Kriesi” I do not know where the change
and the url I do not know where the change.

Perfect! Thank you very much!!!