zenoss 5 how to monitor subprocesses

I have a process that similar to httpd

serverd.*Main -> main process -> if I just monitor this, I only monitor the main process

serverd.*worker-xxxx (xxxx are digits indicating process id, but these processes come and go). but we need minNumber of them.

i thought i could just say minimum minNumber and match just serverd.

In that case, however, zenoss matches all of them 1 by 1, and alerts whenever a subprocess is replaced.

I am wondering if there is a way to monitor:

1. the main process should there (this can be done already)

2. there are at least minNumber of subprocesses. -> this is what I cannot figure out to do on my own because if the regex matches the subprocesses, it creates 1 OS process for each, which is not what I want.

Thanks for any help!