Hi,
Well i don't know UniServer, but i suppose that it's some kind of a package including Apache, Php, MySql and, somewhere, PhpMyAdmin.
For MySql all you have to know is the server's name (localhost for you), and the user name and password, in general by default "root" and nothing (nothing at all).
So go to PhpMyAdmin and check how it works. If it's working, you can find, in the directory where PhpMyAdmin is located the config.inc.php file.
You'll find in this configuration file something like that :
$cfg['Servers'][$i]['host'] = 'localhost'; // MySQL hostname or IP address
$cfg['Servers'][$i]['port'] = ''; // MySQL port - leave blank for default port
$cfg['Servers'][$i]['socket'] = ''; // Path to the socket - leave blank for default socket
$cfg['Servers'][$i]['connect_type'] = 'tcp'; // How to connect to MySQL server ('tcp' or 'socket')
$cfg['Servers'][$i]['compress'] = FALSE; // Use compressed protocol for the MySQL connection
// (requires PHP >= 4.3.0)
$cfg['Servers'][$i]['controluser'] = ''; // MySQL control user settings
// (this user must have read-only
$cfg['Servers'][$i]['controlpass'] = ''; // access to the "mysql/user"
// and "mysql/db" tables)
$cfg['Servers'][$i]['auth_type'] = 'config'; // Authentication method (config, http or cookie based)?
$cfg['Servers'][$i]['user'] = 'root'; // MySQL user
$cfg['Servers'][$i]['password'] = 'YourPassword'; // MySQL password (only needed
// with 'config' auth_type)
$cfg['Servers'][$i]['only_db'] = ''; // If set to a db-name, only
// this db is displayed
You have everything you need.