JavaHelp and root node

[marcodepe]

hi,
Simplifying i have a java help set as this

ROOT -> C
-> B -> b1
-> b2
-> b3
->C


I can set B as current visualized node with these instructions:
helpBroker =(DefaultHelpBroker)coreHelpSet.createHelpBroker();
helpBroker.setCurrentID(B);

my problem is that i'd like to hide the other nodes setting B as tree
root node so that i could only see B and its children b1,b2,b3.
This is because entire help set is recovered from a big manual
describing a lot of applications and i'd like to show only one referred
by node B avoiding to show others that couldn't be installed.
Can you help me?
thanks