Look at the source: Neuz/WndTitle.cpp
Code:
void CWndSelectServer::OnInitialUpdate()
//you find at the end of method this line or something differents
if( script.Load(MakePath(DIR_THEME, "TexBannerList.inc" )) )
than you look in the TexBannerList.inc in the Theme folder and you find the image file of banner and can change the banner..
