How to include multiple lines of matched content in an alert message?

[Dmitry Dzhus]

A certain program runs on my machine on a regular basis, writing
several messages into a log file /var/log/foo.log:

Feb  3 16:04:10 lehost foo[25293]: > Starting up
Feb  3 16:04:10 lehost foo[25293]: > Current working directory is 
/home/dzhus/foo
Feb  3 16:04:10 lehost foo[25293]: > Successfully performed 6 out of 12 
conversions
Feb  3 16:04:10 lehost foo[25293]: > Failed on [14321, 4215, 23591]
Feb  3 16:04:10 lehost foo[25293]: > Powering down

Is it possible to make monit send me the whole set of messages between 
«Starting up»
and «Powering down» in a *single* alert?

File contents check can only match a single line of a file.
Alerts generated by file size checks do not include new content in alert 
description at all.