That object basically gives Max/MSP free access to a tuning library of 3,400+ tuning files: you just have to replace the mtof object with the mtx_loader object in your synth patch. The library comes packaged with the Max Magic Microtuner demo.
Just updated the specs page to version 1.2, with all the bug fixes and the new features added during the past few days upon user request. The source code of version 1.2 is also attached here. Converting this project to Windows should not require a huge effort.
Thanks to the people who privately pointed me in the right direction: I used the Cygwin gcc compiler and obtained a Windows version of the mtx_loader object. All details (including the Mtx archive and source code) here: