JavaScript - Mailto; CC，输入文本字段的主题区域

I really need some expertise. I have developed a PDF Template with a button "SEND"; the purpose of this button is to send the entire template (PDF) to a certain email and a certain CC email. This is no problem to compute in Adobe X Pro. But, I also want to incorporate subject area in the email. This subject area must refer to a specific textbox in the template.I really need some expertise. I have developed