maybe this works:
$more=preg_replace("/((http:\/\/www.mysite.com){1}?(.?)(ACCOUNT_NAME=){1}?\?(.?))\s/i","<a href=\1>\5</a> ",$more);
I didn't test it, but if all works well it makes a link wich links to the complete url (including the GET variables) and places the value of the variabele 'ACCOUNT_NAME' as diplay text.
Is this what you needed?
(in my former post i assumed you just wanted to take a complete url out of some text and make it a link. sorry.)
hope it works