where to put an <a href link for quick jump to reply

Hi,
I am trying to add an <a href link when on an individual listing
I can add the anchor in the sidebar where the reply form is quite easily.
But where would I insert the ‘reply to Ad’ <a href for the actual link to it.

Reason for this is, when using on a mobile version, the sidebar comes after the main page, so it’s not obvious where you reply to an Ad unless you scroll the page right down.

Or alternatively (or just so I and maybe others know) where and what would I insert, so that the ‘reply form’ (or widget for that) appear right under the Ad you are displaying? (rather than in the sidebar)