Create Countdown Timer in Captivate

We are creating a quick game-type Captivate where the user has one minute to answer a few questions. We want to display a countdown timer on the screen in MM:SS format (1:00, 0:60, 0:59 etc). At the end of the minute, we want to redirect to a "Opps! You ran out of time!" screen.

And we need to publish in HTML5 for web and mobile delivery. I am running Captivate 6.1 (but could bump up to Cap7 if that helps). I have played around with the Timer widget, but am nervous about it's HTML 5 compatability since it looks like it was still incompatible earlier in 2013.

I set up variables & actions like http://blog.lilybiri.com/quiz-showing-elapsed-time, but that's showing elapsed time not a countdown timer. And it displays a long string for the time (miliseconds). I'm thinking I can create a variable vTime and then use an expression like vTime = 60 - cpInfoElapsedTime. But I can't find anyway to truncate the time so it only shows 0:60, 0:59 etc. Is truncating possible?

As a backup plan, I also am considering just showing staggered captions, each displaying for one second, to simulate the countdown (like suggested here: http://forums.adobe.com/message/5270717) yet cannot figure out how to get this to display over all slides. I would need to make a project that only had one slide for all the questions. Everything would be hidden and triggering something else... very complicated! My other backup plan is to give users 20 seconds per question using the same setup. At least then I only have 1 question per slide!

Anyone have any success creating a countdown timer? Any other ideas? Thanks!