Cannot execute cmd if fbx-conv.exe is in a path with spaces

[mokalux]

Thank you for making fbx-conv.exe!

On my windows 10 64bit machine I cannot run this command if the path has space in it:
cmd start C:\temp\New folder\fbx-conv.exe -f -v -o G3DJ "C:\temp\male_lp.fbx" "C:\temp\male_lp.json"

Although this works fine:
cmd start C:\temp\New_folder\fbx-conv.exe -f -v -o G3DJ "C:\temp\male_lp.fbx" "C:\temp\male_lp.json"

I tried putting quotes around fbx-conv.exe but that didn't work:
cmd start "C:\temp\New_folder\fbx-conv.exe" -f -v -o G3DJ "C:\temp\male_lp.fbx" "C:\temp\male_lp.json"

cmd start "C:\temp\New_folder\fbx-conv.exe -f -v -o G3DJ" "C:\temp\male_lp.fbx" "C:\temp\male_lp.json"

Do you know if there is a way to have it run even with spaces in path?

Thank you.