In order to configure CS-Cart to work properly with another domain, you should modify the config.php file.

You should change this line:

$cscart_https_host = 'oldcomain.com';

to

$cscart_https_host = 'newdomain.com';

If you are using SSL, you should also change this line:

$cscart_https_host = 'olddomain.com';

to

$cscart_https_host = 'newdomain.com';