Steve,
When I did it I just insulated my wire with some plastic tubing where it touched the opening of the tank. Just get you wire long enough so the anode hangs about in the middle of the space. I used some scrap steel cut-off pieces for the steel anode.
This picture shows 2 wires with sacrificial pieces, one for either side of the baffle. One wire already had insulation on it, so no need for the tubing.
