I haven't used witch hazel in soap but use it routinely as a facial toner. I have no idea if any of it's properties would survive the lye beast but if you want to give it a shot be sure to simmer (not boil) off the alcohol first, like you would with beer or wine. Hopefully someone with more info will come along shortly!
It says right on the label that it contains 14% alcohol so I wouldn't risk it in CP unless you boil off the alcohol. I have purchased the Thayers brand alcohol-free witch hazel and used it in CP but didn't do a full water replacement (more like 30-40%). It turned out to be nice soap and didn't do anything funky like speed trace.