Hi !
Thank you all for your answers !... even if the last one doesn't sound pretty optimistic.

It seems to be a really hard target, but even if I'm almost sure of being unable to break it down, I'm just going to start a 'step by step' approach.
First, I'll follow niom's advice and try to use windbg instead of SI. Even if I'm not familiar with this proggy.
once again, thanx.

bye