BELIEVE IT OR NOTWhile fiddling with the .MDT files and communicating my findings with HertzDevil, he managed to directly convert the weird .MDT (MDRV98) songs to PMDMML! Using MC.EXE, he generated WORKING songs. The way he generated the .MML files is unknown, but he left me with a download to 2 of the songs in the PMD format: "A Sacred Lot" and "Eternal Shrine Maiden". Using the method in the topic below, you can convert the songs to RCP and then MIDI. The songs will be available when the entire HRtP soundtrack is converted successfully.
His message can be found here:
http://i.imgur.com/kEe5zPF.png