Firt of all, by using Hide IP trial and entering any word, or number of letters into the activation key box will activate it.
Second, Limewire is not going through it, it connects directly to the network and i am not sure about a workaround for that. You might want to check the faq's at their website, or if you've paid fo such a service, then they might have some kind of e-mail technical support, or even by phone where you can ask oyur questions more specifically....