fender acoustic electric and line in

i have a fender dg11e acoustic electric guitar with built in pickup. i'm looking to connect this guitar to my macs line in. When i plug straight in i get no sound though. I read some of the other forums and understand a mic may have better sound but i'd still like to get this to work. I checked the guitr and don't see a place to put a battery so i don't think the pickup needs one. do i need a preamp or something else? thanks