You dont have to make an addon at all.
All You you need to do is extract PHPMyAdmin2.x to wamps www folder. Open you browser and go to [
localhost] and away you go
To configure phpmyadmin just copy the default config file (i think its called config.default.php) from the scripts/ directory to the root directory of phpmyadmin2.x rename this file to config.inc.php and edit it to your needs