Using Piwik to track UserPie login usernames

Hello all -

I have Piwik installed to track visitors across my site which utilizes the UserPie login framework. I would ideally like Piwik to be able to track the username that which a user will use to login so that I can easily tell who is accessing my website.

I used to have a Wordpress installation that ran a plugin that tracked the Wordpress username as “visitor”.

Can anyone specify how this could be done under the UserPie framework?