For your Game Commander, set it up in your desktop/Control panel/Game Controllers first. As for your JR 378 not working, take your adapter with the JR lead attached to an electronics guru and get him do do an internal bridge in the plug. The JR system only uses 2 terminals. To verify this before you do it, plug in your JR Tx and pull the plug out slightly from fully seated and you will see what I mean.

Hope this helps
Alan