how do I add a button for vids etc

[Femphysiques]

I had someone admin my board...but he doesn't have much time to do it much anymore...so I'm left to fend for myself...and I'm a duh when it comes to code....can anyone tell me how to ad a button similar to the youtube button where anyone can post a vid? I don't want thme to upload it to the server...just link to it....I guess that's called bbcode?......I tried and failed miserabley to make heads or tails out of the youtube code to see if I could make it work....I guess the variables would be the url and name of the vid...I'd like it to be/work similar to how the [img] thing works....thanks in advance