1. Unzip the jdbc zip file on you server, note down the directory location. You may decide to dump that into $JAVA_TOP, but please do not clutter JAVA_TOP in apps.

2. Open jDeveloper, and ensure that your project has in its CLASSPATH the entire oracle FND Classes. You may need to FTP those classes from $JAVA_TOP/oracle/apps/fnd to your PC.
Although, I vaguely remember that FND Classes come bundled with patch 4573517.
Develop your java concurrent program class xxInterfaceFromPeopleSoft, by implementing class JavaConcurrentProgram

3. Navigate to Application Developer responsibility, Register concurrent program executable xxInterfaceFromPeopleSoft of type java

4. Define concurrent program, and in option field enter the CLASSPATH. See the next step carefully.

5. CLASSPATH...you can either change the CLASSPATH of the Oracle Apps environment or you can override the CLASSPATH per concurrent program. I think the decision will be driven by how many Java Concurrent Programs you plan to develop.
Anyway, in the option field, include the following directories with their absolute path
$JAVA_TOP:apps.zip with path:appsborg.zip:your custom directory where java/jdbc files will be stored. 

6. In java concurrent program do this....
Inside main
-->Open JDBC connection to Sql*Server
Note: - You already have a connection object for APPS, given by CpContext.getJDBCConnection()
-->Here lies the beauty, you have now connections to both SQL*Server and Apps in one single program.
-->Get the records into result set.
-->Call the PL/SQL wrapper code, which in turn will use TCA API’sYou can write into Concurrent program log within java concurrent  program.