sql query remove links

[Danielgsc]

First of all, sorry my english.
Well, I would like to do a sql query to remove all the links in a subforum (id=xx).
Like this
update post,thread
set post.pagetext= replace(post.pagetext,'http://www.*************')
where post.threadid=thread.postid
and thread.forumid=xx

But instead of http://www.**********
What syntaxis (Regular expressions, I supose) must I use to say that it should remove all the words, signs... that exists between

 and

?

Thanks in advance.