Category Walker logic issue

[Eric]

When I want to e.g. intersect "Scores published by (someone)" and "Scores not engraved by Engelmann & Mühlberg" (for example), the category walker always gets hung up on that ampersand, possibly treating it as a logical & (and stopping there, since it seems that category walkers don't do more than 2 intersections - but that is not my question!) rather than as part of the name of the engraver. Is there a way around this? Even better, is there a way around this that can be built into the system rather than requiring that the user be an expert? Thankee...