GWT using domain models /services from external module (jar) ?

[ashika umanga]

Greetings,

We have been using our reusable "user-management" module which was
written using Spring/Hibernate(using Doman-Model Pattern).We have used
that module in several project integrating with Wicket,JSP and ZK
frameworks. Now I am going to develop an application using GWT.I am
completely new to GWT and I noticed that the domain objects should go
inside "xxx.xxxx.client" package. But I want to use our reusable
module (jar) and the domain model is in completely different package.
How can I use my domain-model object from this external library in
GWT? How about service interfaces? Do I have to write proxies for them
too?

thanks in advance