Thanks for the help Bastian!
At the end I made a simple JSP page which gets the XML from the server with the given oauth token, and from the B1if atom I am just calling my page.
So at the end the connection setting is just this:
<destProtocol>http</destProtocol>
<destHost>127.0.0.1</destHost>
<destPort>8080</destPort>
<destPath>/MyIntegration/getData.jsp</destPath>
<query/>
<proxyHost/>
<proxyPort/>
<method>GET</method>
<authentification/>
Thanks again!
Laszlo