Logitech Harmony 1100 Universal Remote Control

To go into detail, I have a Yamaha receiver, a Directv box, and a Sony Blu-Ray player. These are hooked up in a kitchen cabinet 30 feet from the TV and I use a Harmony remote to control all these. I have one HDMI cable going through the wall connected to the TV. Question is where do i plug my a/v cables for the Xbox into at on the Yamaha receiver so the HDMI will make the jump to the TV. I have read other posts and i see where people say that you have to buy additional cables, but I have hooked it up like this (without additional cables) one other time and it worked. I just can’t figure out how to do it again. I am successful this time in getting audio, BUT NO VIDEO by plugging the XBOX a/v cables into the front V-AUX port on the front of the Yamaha. But i know i hooked it into the back of the receiver before and if i remember right, i unplugged one of my jumper HDMI cables and plugged it into something else. Please help, I am trying to get this hooked up for my son’s birthday party this weekend. Thank you so very much in advance!!!
To the Xbox Expert….did you not see hwere I said I have done this one other time before? You need to quit point boosting with ridiculous answers.