Mailchimp custom template required - need knowledge of mailchimp markup language

I need to be very clear on the requirements here - we are after a MAILCHIMP TEMPLATE - ie coded with mailchimp markup language and html.
We now have a completed html newsletter which can be adapted or used for basis of new mailchimp newsletter.
Newsletter to allow for main copy and images to change within mailchimp.
The completed template must be ready to imprt as MAILCHIMP TEMPLATE.
Invoice to be paid on succesful Mailchimp Inbox Inspection.