You could send the command

 LISTS DETAILED

which will make LISTSERV send you back a (long) e-mail containing the headers
of all the lists on the machine, which could then be saved and grepped...
or you could write a short script to run 'listview -h' against all of
the .list files in ~listserv/home and redirect the output to a file which
could then be grepped.

Nathan