Configuration of webservices with grails and WSO2

Hi all

Since I can't find any documentation nor API for WSO2 WSF/Spring I am forced to write to that forum.
I am working with grails and the axis2-plugin. Currently my exposed services work fine. Now, I would like to add a password callback handler to one specific service. Since the axis2-plugin does not provide a axis2.xml nor a services.xml (it is all configured by Axis2GrailsPlugin.grooy), how can i configure my self written PWCallbackHandler for the one service?

Thanks for your help
ced

(By the way: I am using it for my Master Thesis :-) so its quiet urgent...)