Jack support for Windows has recently become available. To use it with HD24connect, you will need to install jackdmp which can be found on http://jackaudio.org/download/. Download a package for your platform and install it.
Once set up, you will need to make sure that HD24connect can access libjack.dll (possibly named libjackdmp.dll or similar) by copying it to the HD24tools directory and naming it appropriately. To manage connections, you'll want to use the qjackctl.exe program.