How do I do this showing the actual clip not just a link?
Convert the video clip into a GIF. Reduce the size many times so the board's image proxy allows it (3MB I think?). Highly unrecommeneded, but probably the only option to show the actual clip.
there is a flash link in the toolbar, would you know how to do it that way?
It's used like this:
[flash=x,y]flashLink[/flash]
Don't know if the forum has it enabled, as most don't since it's a security risk.