You may want to suggest it in the DragonCon thread on this site, if you haven't already. If the DragonCon site has a forum for attendees, try joining that and pitching the idea. It may be difficult, however, to separate the EGL/EGA/etc. category from typical cosplaying contests, since many people consider the line between EGL and cosplay very blurry, if they realize it exists at all. The other thing is, if you're not viewing lolita-style as a costume but rather as a regular fashion, it probably isn't going to be awarded its own competition since you'd essentially be giving someone a prize for their street clothes.
"And we are all told from the moment we open our eyes, that everyone is entitled to his or her opinion. Well, that’s horsepuckey, of course. We are not entitled to our opinions; we are entitled to our informed opinions. Without research, without background, without understanding, it’s nothing. It’s just bibble-babble. It’s like a fart in a wind tunnel, folks." --Harlan Ellison