how to filter word file "save" operation?

Dear all,

My filter can filter the read and write operation on a .txt file, however,
it can’t make it on .doc file “save” operation. i.e., in IRP_MJ_WRITE
handling routine, no way can detect the write operation on word file.

I understand there are some rename tricky for word file during “save”, and I
use file name to filter its read/write operation, so that is why I can’t
make it.

If so, how can I solve this problem?