Also it helps to add paths to the exporter script's wizard section.
Here's a example screenshot of it:
Add the paths you DON'T want to include in the path string your mesh file eventually will have. For example if you recreated the game's folder structure in C:\bfheroesDEV\
Then add this:
I'm not sure if the path should include the Objects folder or not. If not, then include that in the path string.
It all depends on where you put all your textures.
You can open a mesh file in a hex editor or notepad and find how bfheroes pathed to the textures by going to the bottom of the file. You can also change the path using a hex editor so long as the path is the same size as the old one byte wise. (you can't add more letters to a path then it started out with in the hex editor) If the filesize of the mesh file changes after you hexedit it, then it means you removed a letter or added one and this will cause a crash during load.