Creating a post via javascript

Hello, we have a custom form on one of our community pages that submits to an external server. We would like to simultaneously create a post in our Lithium forum, using only javascript/html, which replicates the content of this form submission, so that members can see what information other members have been submitting. Is there a way to submit a new post as a form or as a get request, without using the rest api?

Thanks.