Are there any applications that can write to ext4 file systems from Windows?
I have not tested this, but this project's driver claims to be able to let Windows access it. Whether there are specific applications that can, or cannot, use it, you would probably just have to test.
and the FAQ says that these systems are supported:
I would be wary of these drivers, in general, not this one specifically. As I was searching, I found numerous warnings regarding the possibility of lost data, so make sure you are backed up. I did not find any actual cases of lost data though.