Numbering question slides (question # of #) from question bank?

I would like to add "Question # of #" to the bottom of my question slides, to let the user know what question number they are on out of how many are required.  This is fairly straight forward if I am just creating the question slides and adding them directly to my course, as I can manually enter a text box on the bottom of the slide with this information.  However, when I use the question bank feature, it becomes a challenge to me.  My scenario is this... I have a question bank with 20 questions, which I want the system to randomly pull 10 questions (in random order) when the user takes the course.  When the quiz is started, I want it to show "question 1 of 10" on the first question slide, "question 2 of 10" on the next one, etc., etc.  

I am sure there is a javascript and/or variable which will give me this flexibility... I just need to find it!  Any suggestions would be greatly appreciated.

Thanks,

Bobbi