I'm not certain that i understand exactly what you are describing, but there was some discussion a while back that may be similar...
http://issues.apache.org/jira/browse/SOLR-109 ...there's not a lot in the issue itself, but the linked discussion may be fruitful for you. if what you are describing is the same thing then i certianly think it would be a handy addition to SolrQueryParser and the core request handlers. : Has anyone spun thoughts around something like a "solr.ParmSubstHandler" or any way to pass maybe a special : ps=0:discussions; ps=1:images; ps=2:false -Hoss
