I can point you in the a direction that may help but nothing more than that:
There used to be a port of J2ME VNC for BlackBerry: J2ME VNC - Blackberry port
Not sure if it still works
You can try the actual application that is still developed at:
If you have any questions I can try and help but I would highly recommend one of the Idokorro/Rove products. I gave up on the free solution it was just not optimized for mobile devices.