I have created a Help plugin and am trying to deploy it as a war file.

I am following the instructions in the Eclipse Help at
Platform Plug-in Developer Guide > Programmer's Guide > User assistance support > Help > Deploying the infocenter as a Web Archive (Help - Eclipse SDK)

The first few steps are:
In your Eclipse installation locate the plugin org.eclipse.help.webapp.<version>.jar and copy it to a temporary directory,
unzip the copy into that folder.

1. In the webapp plugin locate the web-archive directory and underneath that there will be two directories titled "help" and
2. Import the org.eclipse.help.infocenter-feature using File->Import->Existing Project.
3. Export org.eclipse.help.infocenter-feature as a deployable feature and set the destination to be web-archive/help/WEB-INF/eclipse in the area where org.eclipse.help.webapp.<version>.jar was unzipped.

When I attempt to do step 3 (the export as deployable feature part), I get the following error:
Processing inclusion from feature org.eclipse.help.infocenter_feature: Unable to find plug-in: com.ibm.icu.source_0.0.0. Please check the error log for more details.

Can anybody advise me on what to do here ?

I am using Eclipse Helios and Tomcat 5.5 on Windows XP.