Custom Admin Page
I use these for those occasions when I need to store specialized information in non-WordPress tables. (Such as orders in a custom shopping cart I built.)
It’s also handy for adding informational or instructional pages to the Dashboard.
This adds the page to the WP admin menu (put in your functions.php file):
The page itself ( lt_orders.php ) resides in the theme folder, and is a simple PHP page, with any functionality you like. It doesn’t need any header or footer calls because it is rendered inside the admin.