Create a custom woocommerce shortcode and post variables to paypal

We are creating a website with this theme [login to view URL] Here is a description of the site's current functionality: The theme allows visitors to post classified ads and allows us to charge for the posting of the ads. We have the website setup to require a free account to be able to post ads. The members don't get any free ads so they must first purchase their ads through woo commerce. The theme has added code that allows us to create products in woo commerce that are called packages. We will have 3 different packages - 1 rent ad, 1 sale ad, and 1 share ad. Currently when you purchase a package you are given the ability to post an ad on the site. Here is the functionality we want added to the site: Add a custom variable (Ad Type) to the pricing page buttons (rent, sale, or share) to be passed to paypal. Create a custom version of the [woocommerce_checkout] shortcode with additional fields: Title - Textbox Category - dropdown (options already exist on website as an ad taxonomy) Sub-category - dropdown (options already exist on website as an ad taxonomy) These variables will be passed to paypal also. So the 4 custom variables that we will be sending to Paypal are Ad Type, Title, Category, and Sub-category. POST the values to paypal and store the values in the database when they are returned from paypal. Write a function to automatically create an ad for the user and fill in the appropriate fields with the appropriate values from the custom [woocommerce_checkout] form. We will need these fields to be displayed in the back end as columns in the Woocommerce orders page and the order details page. On the Woocommerce orders page we want it to replace the Billing column. If displaying it on the Orders page is a difficult task we don't need it there as long as it's displayed on the order details page. Lastly we will need you to disable the fields in the 'edit ad' form - Title, Category, Subcategory, and Type of Ad.