There are a couple of convertors, one from Rutex and another from here
http://max-mod-shop.com/index.php?option=com_content&view=article&id=47:yapsc10v&catid=17:-yapsc&Itemid=4 Dont know anything about either and have not heard of anyone using them so you will have to do your own research
The other options are the DSPMC
http://www.vitalsystem.com/web/motion/dspmc.php and Dynomotion
http://dynomotion.com/ , they are external motion controllers which connect to Mach via plugin. The DSPMC seems to have a lot of happy users but not seen much about the Dynomotion
The last option is Galil.
Hood