Dynamic value

CF7 has shortcode for user’s ip adress to be sent my mail, but I need to fill IP adress inside hidden field’s value, so I can use this field with mc4wp plugin and send it to mailchimp.

Is there a way please? I know that there is a plugin for dynamic values, but I didn’t came this far to use a plugin in the end. Want to code it myself if it is not too much work.