Adding a classpath entry

I'm trying to follow an example where someone accessed application 2 from application 1.using GWT. A quote from that methodology is:

After adding "]]>" to
com.app.App.gwt.xml, adding "%~dp0\src\com\test\client" to the
classpath in App-shell.cmd and adding "import
com.test.client.Widget1;" to App.java, Widget1 appears in host mode
run of App.java.

My question is where can one edit the classpath to add something like: "%~dp0\src\com\test\client"