Pelo que entendi, o que você necessita é fazer o upload de arquivo para uma determinada pasta. Utilizando webscripts (como você está tentando fazer) a melhor solução seria criar um webscript customizado, para que ao enviar o arquivo, envie juntamente o nodeRef do espaço de destino.
Um bom começo é pela WIKI do Alfresco, que mesmo que um pouco desatualizada, tem excelentes conteúdos que podem te auxiliar no dia a dia.
<tr><td>The Web Script <a href="%2Falfresco%2Fservice%2Fapi%2Fupload%2F%3Falf_ticket%3DTICKET_b9608b67527a48401387c7078b8e8b1bac6410b3">/alfresco/service/api/upload/</a> has responded with a status of 404 - Not Found.</td></tr> </table> <br/> <table> <tr><td><b>404 Description:</b></td><td> Requested resource is not available.</td></tr> <tr><td> </td></tr> <tr><td><b>Message:</b></td><td>00170093 Script url /api/upload/ does not map to a Web Script.</td></tr> <tr><td></td><td> </td></tr> <tr><td><b>Exception:</b></td><td>org.springframework.extensions.webscripts.WebScriptException - 00170093 Script url /api/upload/ does not map to a Web Script.</td></tr> <tr><td></td><td> </td></tr> <tr><td></td><td>org.springframework.extensions.webscripts.AbstractRuntime.executeScript(AbstractRuntime.java:173)</td></tr> <tr><td></td><td>org.springframework.extensions.webscripts.servlet.WebScriptServlet.service(WebScriptServlet.java:118)</td></tr> <tr><td></td><td>javax.servlet.http.HttpServlet.service(HttpServlet.java:717)</td></tr> <tr><td></td><td>org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)</td></tr> <tr><td></td><td>org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)</td></tr> <tr><td></td><td>org.alfresco.web.app.servlet.GlobalLocalizationFilter.doFilter(GlobalLocalizationFilter.java:58)</td></tr> <tr><td></td><td>org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)</td></tr> <tr><td></td><td>org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)</td></tr> <tr><td></td><td>org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)</td></tr> <tr><td></td><td>org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)</td></tr> <tr><td></td><td>org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:433)</td></tr> <tr><td></td><td>org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)</td></tr> <tr><td></td><td>org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)</td></tr> <tr><td></td><td>org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)</td></tr> <tr><td></td><td>org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)</td></tr> <tr><td></td><td>org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845)</td></tr> <tr><td></td><td>org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)</td></tr> <tr><td></td><td>org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)</td></tr> <tr><td></td><td>java.lang.Thread.run(Thread.java:619)</td></tr> <tr><td></td><td> </td></tr> <tr><td><b>Server</b>:</td><td>Community v4.0.0 (7) schema 5.025</td></tr> <tr><td><b>Time</b>:</td><td>17/01/2014 14:32:33</td></tr> <tr><td></td><td> </td></tr> </table> </div> </body> </html>