Wiring GE smart switch in 3 way configuration

I just got a GE Zwave In-wall Wireless Smart Dimmer and can?t connect it to my current wiring because the wiring I have in my hallway is different than what is in the manual. I want to connect the dimmer smart switch with an in-wall add-on switch in an already 3 way switch configuration. The manual only shows a set up where the incoming power goes to the switch first. In my situation the power goes to the light fixture first then comes down to the first switch then the first switch is connected directly to the second switch without any lights in between. This kind of wiring schematic does not give me a load wire to go to the light. Can someone help?