JPortable and BT747

Dear PA-community,

I tried whether JPortable supports the Java-based GPS-logger software BT747 (http://www.bt747.com/) or not. JP is installed in the CommonFiles/Java folder, and I've put BT747 into PortableApps/BT747. Unfortunately, neither does BT747 find the portable JRE, nor do I see any process or application related to Java in the task manager after I having startes the PA menu launcher.
I can start single BT747-JAR files (in BT747/dist) using the JP-Launcher app, but some important functionality of BT747 is always missing then.

What can I do to try to resolve that issue?