If you don't have a PTO on your machine, you could drive a hyd pump, off of the front of the motor, and use that to add a fully live system. Or, if you have a valve bank, for other hyd functions, you can add a valve section, to that, for winch function. Any way you slice it, its gonna take finding a hyd winch. Once you find your winch, then you have to determine whether it will work with the flow and pressure of your system, or whether you will need a pump to mount on front. Do some research, on hydraulics, if you need parts, to cobble something up, check out Surpluscenter.com, they have an excellent tech help page, with hyd formulas, as well as sometimes stocking hyd winches, pumps, and other components...
https://www.surpluscenter.com/