You would use this as the BB Code replacement text:
Code:
<iframe src="http://www.flvz.com/embed/{param}-l.html" width="720px" height="550px" marginwidth="0" marginheight="0" hspace="0" vspace="0" frameborder="1" scrolling="yes" allowfullscreen='true'></iframe>
And then you'd use something like this for your bb code:
[flvz]d9437e0adaad113a624492a14ade4962[/flvz]
Assuming you called the bbcode
flvz.