CSS counter in url

[Miloose]

I am interested in setting the images next to list items dynamically based on it's position. You can see below that I am using the counter feature of CSS to keep track of the list items, and that I am trying to specify an image as the list style type using the counter. \[code\]ul{ counter-reset:list;}li{ counter-increment:list; list-style:disc outside url("http://dummyimage.com/" counter(list) "x" counter(list) "");}<ul> <li>Item</li> <li>Item</li> <li>Item</li> <li>Item</li> <li>Item</li></ul>\[/code\]What is the correct way of getting the counter to work in a url declaration? Is it even possible?