To put a hotlink into this forum you need a slightly different method from that used in "normal" fora. This one will accept standard HTML tags embedded in any message which most do not. The HTML tag for a link is "a" (for anchor) and at a minimum it needs an URL and some descriptive text. In the following example I have added some underscores so that your browser won't interpret the code as HTML.
Here's an URL:
http://en.wikipedia.org/wiki/Butterflies
and here's the HTML code which will turn it into a link:
<_a_ href="
http://en.wikipedia.org/wiki/Butterflies"_>_This link will take you to the Wikipedia Butterfly home page<_/_a_>
So, taking out all underscores from above we get a clickable link like this:
http://en.wikipedia.org/wiki/Butterflies">This link will take you to the Wikipedia Butterfly home page
I hope that all works or I will look very silly.