Use the globe icon, 3rd from the left on the bottom row & place the HTTP address between the two url's. Then remove the first "]" & place an "=" sign between your HTTP address & the url. At the end of your HTTP address put the "]" back in. Now between that "]" & the next "[" put any title in you want to call it.
I'm going to post this despite the nagging suspicion that I'm being really dumb and missing something REALLY obvious however....
In the old site when you posted a link to a web site, you firstly put in the http address and then another box came up with what you wanted to name it. I have tried to do this with the new site with no success, yet I have seen others doing it no problem. Any help would be much appreciated.