I'm having the same problem, and from what I've found thus far is that if your tomcat server is on the same box as the weblogic server, you can use the wlclient.jar and the t3 protocol to communicate. However, if (as in my case) the weblogic server is remote to the tomcat server it looks that you must use iiop and wlclient.jar to communicate. I've been unable to confirm this, and I haven't successfully communicated in this method either.
I’ve looked at a lot of different solutions, and in my humble opinion Aspose is the way to go. Here’s the link: http://aspose.com
subject: Correct Weblogic client libraries for Tomcat 4.1?