Cred to Paypal without Woocommerce

I am referring in part to this post: http://wp-types.com/forums/topic/feature-request-add-calculation-to-cred-cred-commerce/

I would like to know if there is any way to pass variables from CRED to Paypal direct. I do not need Woocommerce for what I need to do, so a simple form to paypal would do it. Paypal actually have guidelines on how to do this with a normal form, but I am not sure how this would work with CRED:

Here are the Paypal specs http://www.paypalobjects.com/en_US/ebook/subscriptions/prepopulate.html

Thanks