Patrician...I tried to search this with not much luck.  I guess you are
using "google groups" to read your newsgroup posts (I believe Gmail is just
for e-mail only, and I think you have a filtering system in that).  I don't
mess
with "google groups" and don't know a lot about it - I have used the
"advanced
search" feature.

The following snip from "google groups" states that there is no way to block
posts in "google
groups" -

[[On Jan 25, 8:39 pm, DerekW wrote:

Nope, we've all been requesting this feature since the beginning of
Google Groups, but no response]].

Sorry, I don't think there is a way to do what you want in google groups.
You will probably need a news server and then a newsreader like outlook
express or thunderbird.  There are various free news servers (I believe most
of them have a nominal initiation free), but most of them suck and are
unreliable and many may be "read only" and they may expire at any time
(especially if they are totally free) - da da da da.

Pete

Is  Mozilla/4.0 your news reader?   I saw that in an earlier post, but not
in this one.