url_regex matchint any IP

[Alfredo Rezinovsky <alfredo@xxxxxxxxxxxxxxxx>]

I'm trying

acl dotted_ip url_regex -i 
^http:\/\/[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\/

to match any ip address hostname.

I don't need to be strict, http://999.777.555.333 could match and I dont 
care.
The problem is that my url_regex doesn't match ANY ip address.