You need WMV Studio or WMV Studio Pro HD or something in between, one of the paid levels of Flip4Mac. They are all the same QuickTime codec whose varying level of functionality is determined by the price of the license.
On a Windows PC, installing the K-pack video codecs (free - http://www.codecguide.com/download_kl.htm) will allow Windows Media Player to play all those formats. Then the free Expressions encoder from Microsoft will transcode those files into WMV.
If you're not allowed to install that software on your computer, you'll have to use a Virtual Machine or another computer to do your conversion. Sorry, there's no easy way.