Mailchimp PHP API Script Required to add subscriber with customfields

As a novice and beginner coder i am pulling my hair out trying to get mailchimp to work perfectly and seamlessly with the API. I require and email script to install where all i need to do is add my API key. The script needs to have several custom fields such as: fullname postcode estimated-price ip useragent address phonenumber + more... in the script i would like to be able to refer to the custom fields using php variables such as: $emailaddress $fullname $postcode ect ect... My website is vertually finished so its important that i can easily assign my current variables to the mailchimp api custom fields upon form submission as using Mailchimp built in form app is not an option. I am looking for this to be completed as soon as possible, Templates are available online i just need someone who is advanced in coding to complete the script for me. I was hoping to have this done today if possible? Thanks.