Hi, Doug. Unfortunately, that receiver doesn't have the ability to assign audio and video inputs to various sources. To the best of my knowledge, you are limited to the input configurations on the back.
If you meant a Sanyo PLV-Z700 projector, it looks like that has two component video inputs. So, if you have those open, one work-around is to connect the video outputs from the OTA tuner and Wii directly to the projector, and connect the audio from them to the receiver.