To post a video you would use HTTP tags.

You have to upload it to a server that will allow it to be access from PT. Just like you would a picture to imagestation. Then use the HTTP tag to direct the click to the wherever the video is stored. Imagestation will allow video, but it limits the amout. I can't remember how much.

If the video is under about 2.1 megs you can attach to the post.

I hope this helps. I have never done this, but I went to a post that had video and that is how it was done there.

Please let me know if you have any questions and I will try to answer them.