Fasten 4x4 steel posts to concrete wall?

Hi, one side of my property faces an abandoned house, and I am tired of bums jumping the small cement wall (about three feet high) and wreaking havoc in my back yard. They have stolen my water heater, ripped out the cables for my stove, and stolen hundreds of dollars in materials. I would like to put up a fence that increases the height of that fence by about 10 feet, but I don't want to take down the fence that is there now. It's poured cement, not block. Does anyone know of a way to anchor 10x4x4 steel posts to that existing fence so that I can build a sturdy, solid steel fence that won't blow down in the next hurricane? Thanks!