No, he didn't.
Remi Herbulot invented the HERAD music system, which used features of the sound chip that no other sound system did. Remi operated on a godlike level of FM sound production, the only other person who even approached him was Robert Prince (Doom musician).
Stephane Picq wrote most of the Dune soundtrack as real electronic music then "backported" it to Remi's music system. Ulrich contributed one or two tracks.
http://www.vgmpf.com/Wiki/index.php/Dune_(DOS)
You can hear the obvious similarity between Dune and Stephane's other music: