If using a .htaccess file
If placing the rule in a .htaccess file, the .htaccess file into which it should be placed is the site root's .htaccess file, which should be created if it doesn't exist:
G:/xampp/htdocs/.htaccess
Although the store is in a subdirectory, the .htaccess file into which the example rewrite rule should be placed is NOT a .htaccess file within the Zen Cart folder, the rewrite rule below is for the site root's .htaccess file - place it in the above file!
If using an Apache VirtualHost Directive
If the store runs on a server using Apache and it is possible to modify the VirtualHost Directive for the store, then the rule can be modified and entered into the VirtualHost Directive for the store.