[rules-users] DSL expanders for overriding rules question

I have a question about expanders if anyone on might know the answer I'm trying to setup an import scheme for the rules in my system and thought that having expanders be the extension location might work, however when I try to use multiple expanders the eclipse plug-in throws and illegal argument exception. Is this the proper way to include rules and override or is there better way? Thanks in advance, -- Paul Ryan