Transparent PNGs

Hi All

I want to create a video of just the guages in Virb edit so that I can combine this with other clips in Adobe Premier pro.

Last night I tried turning on the transparent png option and compiled a video that was around 40 minutes long.

I did get a folder with PNGs in but I only got about 50 frames. I would have expected thousands of frames.

Does this feature just not work?

If it did work how do I go about adding these individual frames into a video?

Thanks