To add new payment method in My Balance page you need to add new row to payment_methods
display_name = the name that will be displayed in My Balance page
short_name - create folder inside modules/payment_methods/ folder .
In our example folder name should be modules/payment_methods/2checkout
page_name - You need to create 4 files . The file names should start with "page_name" column as below
2checkout.php - code behind file
2checkout_tmp.php - template file
Release your logic in this 2 files . They will be displayed in My Balance page.
you need to create 2 more files as below
This 2 pages will be visible to administrator . You need to release admin interface in this 2 pages .