Filter syntax for attribute containing distinguished names

[GLASSON,Michael <mic...@de...>]

Is there any trick to writing a filter to search for entries whose 'member'
attribute has a particular value? That is, what does a filter to search for
a dn in an attribute look like? This has got me stumped (sorry, I'm
Australian) because I can retrieve records with '(member=*)', but not
'(member=c*)'. Further, this last case returns an error, rather than no
records.

I have been trying to write a recursive walk in perl-ldap to give a tree
structured view of distribution lists in Exchange. To do this, I wanted to
find entries whose 'memberof' attribute contained the dn of the known root
of lists. So my problems have started.