I don't think that's a good idea either , but,,, if I were to do it I would buy a draw bar that has a Reese hitch reciever . That would open a lot of options for a winch. How big of a winch are we talking ?
Made a setup like this about 26 years ago to mount a 3000# winch on for ATV's, it worked great. You put it over a trailer ball or use a chain and shackle to attach it to whatever.