I have made a regex which should work in most languages. But it seems like mIRC don't like it.

Let's just get this random line which I'm testing against:
Code
Vestibulum ante ipsum primis in faucibus orci https://www.youtube.com/watch?v=5gGjRcGdELs ipsum primis in faucibus orci luctus et ultrices posuere


And the working Regex for most languages:
Code
https:\/\/www\.youtube\.com\/watch\?v=[0-9a-zA-Z-_]{6,20}


I guess this Regex is not working in mIRC. If someone know how I should do this in Regex. Please tell me what I do wrong and how the Regex you made works.
I know regex but for mIRC it seems special.