Show comment count in meta description?

This is unusual request, but is it possible to show comment count in the meta description of a page/post? Basically, I’m trying to create a review site and I noticed on another review when when I search for sites they’ve reviewed in Google, it displays the current number of comments (or reviews). So it will say something like “260 Ebay.com Reviews” and that number constantly goes up as more and more people write comments/reviews.

I have tried to add a code into the meta description to display comment counts but the meta tag does not like any sort of coding.