how to find field that has any value

[MATL (Mats Lindberg)]

Hello
 
i have a probably simple question for some of you.
 
Since lucene does not allow a query to start with a wild card (* or ?)
how would i find all documents in lets say field test that has something
in that field, or is not empty.
 
my first thought would be to do something like this.
 
test:________                (cause the value ______ isn't very likely
to be present)
 
 
test:*                            (would be the correct way, i guess,
but lucene doesn't allow that)
 
 
does anyone have a greater idea.
 
Best regards,
Mats Lindberg