you would probably have to actually get it from aol and they would have to look who was using that address at a certain time.
most or all of their members don't keep the same address. everytime a member logs on aol (or any other ISP), they will get a new address, and they even sometimes share ip addresses. plus the fact that their addresses get recylcled.
so as far as i know you would have to get the aol id associated with the ip from aol and they aren't gonna give it up w/o a subpeona... because of privacy polices...
lol trojans... shit man i dunno if AOL is any different, but with WinXP and similar systems, trojans are pretty much obsolete. Shit is hard to use these days