Search by field with WDS

Hi,
I have Windows Desktop Search correctly installed and running. In its
desktop 'modality' it works fine, as well as in its 'embedded' form within
Windows Live Mail. However, in WLM I have only been able to use in its most
basic form: type a word and go. But what if I want to search mails with some
word in the subject? Or by the sender's name?
I have tried to typing things like 'from:john' or 'subjectarty' (as
indicated in the WDS help) but it doesn't work, nothing is found. If I only
type 'john', it will surely find the mails sent by john but also the mails
sent to john, and everything remotely related to john. Not useful.
How can effectively use WDS within WLM to do a field-specific search?
Thank for the answer(s)

Regards.