Aboud,
From what I understand, the SND file bank contains some *INGREDIENTS* in it, which means every *.SND file has few sounds in it. I think this is the same way more or less WINZIP works, you can zip many Wave files together and have a final big file with *.zip extension.
Some other computer wizard here in this forum was able to do something similar for the Korg keyboards: http://www.synthzone.com/ubbs/Forum37/HTML/004135.html

If we can do such a program it will be very beneficial for most of us because it will allow us to make our very own FINAL oriental sound bank using a mix of different banks.

I hope you succeed to do it some day…

Maged