Subject Mail option rolling code/shortcode?

Hey,

My mail does not display any of the CF7 shortcodes. For example if I have [your-subject] included in the email body I get the users subject but if I include it in the mail also I get [your-subject] as the subject for the email. The issue I am having is that this is used for support emails and I am in need of a ‘rolling’ subject or a subject that changes with every support email sent.

http://ww.wp.xz.cn/extend/plugins/contact-form-7/