this sounds quite interesting... 
for my final exam project I played a bit with drivers... mostly USB... but I also looked at some other drivers... to try to learn how it worked etc...
unfortunately I don't know much about MEL scripting yet... I'm mostly educated in Java... and have played a bit with VB and C++... but I would like to help if I can... 
do you e.g. have some more info about your scanner?
regards
Strarup
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Alex V. U. Strarup
One mistake can ruin it all...