Cluster note heads

[Eyolf Ostrem]

While we're at the subject of note heads: is it possible to specify a cluster 
as the tone height? I don't mean the \makeClusters command, since that - as 
several others have pointed out - does not seem to work very well for single 
cluster chords. What I'd like is a sqqare notehead whose note span can be 
specified, but which otherwise behaves as ordinary notes, i.e., it can have 
stems, it can be filled or open (for whole notes etc).
What i've done so far, is specify two very short, identical chords with 
\makeClusters and fill up the rest of the space with "s". Not ideal.
If this is already in the manual, forgive me for not having found it. And if 
it's not - perhaps something to consider?

Eyolf