Adding music to AdvMap terrain.

Dear forum members, are there any of you who have added (not replaced) soundtracks in AdvMap Terrain? I love playing Heroes, even though I'm not a professional at it. But sometimes I want to diversify the game with other soundtracks. I know how to add music to battles, but I would REALLY like it if 2 or more tracks could play on a specific landscape (for example, AdvMapTerrain_Grass) (like in Heroes of Might and Magic V).
Replacing music files is NOT recommended!
I hope there is someone who can solve this problem.