Set the document class to be up a directory?

This may not even be possible, but here’s what I’d like to do.
I’d like to have a structure like this:
/fla
file.fla

/com
file.as

I would like file.as to be the doucment class of file.fla. I tried com.file, …com.file, …/com.file
No go. Anyone know if this is possible and how to do it?

Thanks