XLR... three conductors rather than 2 (used by consumer-grade mics). This allows shielding in the cable to be protected from spurious electromagnetic and radio frequency interference.
So... you apparently don't like my recommendation to not record off the mains or use the AUX-out. Here's another method - presuming your mixer can do this, but since you still have not told us what it is, we have no idea... Use the mixer's headphone monitor. That is normally a 1/4" stereo jack. Radio Shack has 1/4" male stereo (plugs into the board's headphone jack) to two 1/4" female stereo jacks. The person recording gets to plug their headphones into one side, the camcorder is plugged into the other side with a 1/4" male (to the adapter on the board) to a 1/8" stereo (plugs into the camcorder).
This is NOT normal practice, but will be your easiest route out.
TEST THIS BEFORE THE EVENT to ensure the line signal does not over drive the camcorder audio in. If you are expecting to set up everything at the event and hope it magically works, you are setting yourself up for failure and no time to implement a contingency plan.
You still have not told us which audio mixer, which camcorder or which mics - manufacturer and model number are helpful. As well, since this is already being recorded offboard from the camcorder, it is unnecessary - Use the external recording. Import the audio from the external recording when the video is edited and mute the camcorder's audio. You are truly making this harder than it really is, unless there is more to this that you cannot or will not share.
Regarding your reply (see below)
You seem to be convinced
by boya84 - 3/2/09 12:56 PM In reply to: Coming off the mixer by mrdallas1965
that coming off the board is how you will go. You can use splitters wherever you want. It will work to a point. If you are using wireless mics with 1/8" jacks, they are either REALLY good Sennheiser or Sony (pro grade) ENG wireless gear which use mini TRS connectors or cheap, low-end, consumer wireless lavs in FM or some other shared frequency.
If the wireless mics are getting to the board - and the board is feeding some PA speakers, I stand by the recommendation of not using the board. Just mic those PA speakers and don't worry about the rest of the stuff at the board.
Any recommendations as to adapaters that can be used to fit a TRS connector into the mic in on the camcorder?