I've not tried it myself, but there are other members that have done this with their orchids successfully. I don't know if it was the same genus or not. I'd try to search for it, or try out the propagation forum.
I think you just moisten the sphragmum(as in squeeze most of the water out) set the plant on the top of sphragmum in ziploc bag...not sure about the rest... but here's a link it was another beginner, different plant, more links provided in there too.
HELP!!
Good luck.
Melanie