Add RSS Buttons

Hey everybody.
I “added” RSS feeds for single categories to my sidebar.php using

wp_list_cats(‘sort_column=name&optioncount=1&hierarchical=0&feed=RSS’);

and it worked fine, but i would love to have rss icons for subscribing to
the single feeds instead of a textlink saying “RSS” behind every single category.
I was impressed by the wp_list_cats “power” so maybe there is a chance
just to specify an img url so i get the icons behind every category.

Im very new to all this and i dont know if my terms are used correctly here,
All support appreciated, thanks a bunch in advance.

Joscha