Forums / Cotonti / Skins / Theme help

i'm working under themes for my competition skin.
For some parts of the design i needed to put out links like search_{PHP.usr.theme},which would work like search_sed-light...but i cant do such a thing for forum posts stars information(which here is under the Group name) cause its put out by a {USERSTARS ..or something like that} tag,which i cannot edit without touching the core.

So the question is: is there a way to write the userstars tag which would put out stars images according to the current user theme?