custom sign-up form

Hello,

Is it possible to create our own custom sign-up form that posts to the same end-point as a CC Sign-up Form created using the form builder? That way we can customize the form more, but still capture sign-ups to the same end-point so that CC can use the emails in Automations, etc..

When we created an inline sign-up form within CC I was hoping to get the full HTML that I could then edit, and just make sure it was posting to the same end-point, but it looks like the inline forms use CC's Universal JS to embed the form. I'm assuming I could decode that and just find the same end-point and post to it the same way but I wanted to get confirmation first before I spend time on it.

I hope that makes sense.

Please see this post for additional context: 

https://community.constantcontact.com/t5/Questions-Discussions/custom-inline-form-code/m-p/428619#M88471