Foren / Cotonti / Support / Structure desc to textarea

here is the general idea:
I want to make special categories for authors,on which they will put out theyr works.
So this means that i need some logo in every list.First i wanted to make list.tpl's for every category but its will be to much.Than i thought just to put in list.tpl tags like List_caticon and list_catdesc.

can i make this in the next way ? :

change db

put the textboxer for cat_desc in the admin=>structure (this one i dont know how to do)

in list.inc.tpl edit the tag to => "LIST_ROW_DESC" => sed_parse($pag['page_desc']),