Changing page title as it appears in MediaWiki category -

i've been trying use defaultsort sort pages based on template parameter instead of page title. how appears @ top of template:

{{defaultsort:{{{username}}}}} 

this how appears after argument transcluded:

{{defaultsort:d3xus}} 

it nice appear in categories d3xus , not d3xus. there's no change in how page sorted because both begin same symbol. using extension or magic word, possible change how page appears when viewed in category? defaultsort changes how page sorted respect other pages in same category, not change page title in category.

that's impossible without bigger change in code. there task in wikimedia's bug/feature tracking software phabricator: t19212, it's stalled :(