Join? Query? Select?

[Daniele Margotti]

Hi list,
I have a point layer, based on a shapefile.

I also have many .DBF files, which are reduced sets of the original .DBF of
my shapefile (i.e., I have only one field, "ID", that corresponds to
the "ID" field of the original shapefile, and only some records - not ALL
of them).


Now, the problem:

When I browse the map, I want to see ONLY the points that are listed in
my "reduced" .DBF (or, alternatively, see them in a different color -
defining a CLASS item).
Since I use CGI Mapserver, I also want to define a variable (%dbf%) that
should be inserted in the mapfile, so I can modify it to change the view of
my map (without modify my mapfile).


Is it possible?
What do I have to add to the mapfile?

Thank you,
  Daniele