WHMCS payment module customization/development

Hi, I'd like to have WHMCS payment gateway module which allows accept PayPal payments via 2checkout gateway. Currently, WHMCS has 2checkout module and it has a checkbox "Tick to use 2CO Cart Checkout Routine (Shows PayPal Option)". If this checkbox is checked, the customer goes into 2CO system and can choose a payment option: PayPal or credit card. I need a module which send the customer directly to PayPal checkout via 2CO without any selections and questions. This picture describes the flow: [login to view URL] PS. I don't want to use PayPal module and accept PayPal directly. I need accept it via 2CO system.