CustomPress Archive Custom "Sort By"

Hello,

I am using CustomPress for a custom post type.

We are trying to sort our "Polls" Custom Post Type so that ones that have yet to been answered by a User will float to the top so they do not have to dig through endless pages to find a new one.

I am wondering if there is a way to change the "Archive" page to use a custom "Sort By" when querying the database.

Is there any hook / setting that would help me accomplish this, or would this require building a custom archive page template?

Thank you!