PayPal & Contact Form 7

I would like to use Contact Form 7 to setup a donation form for a client. For example, they would like the web visitor to enter their name, email address, and level of giving. I know that I can use the PayPal plugin created to use with Contact Form 7. My question is how do I setup the form to transfer a particular amount selected on the contact for 7 to the PayPal donation page. I would prefer that they don’t have to remember the amount that was selected on the previous screen.