If I understand your post, you have banks of sysex to transmit, but cannot load into Sysx View due to the extension name of the files.
So, what kind of file extension is on the file in question?
How were these files created? Have you tried copying one to a .syx extension and seeing of that worked?
Could the banks be created from source to have the correct extension?
I have no trouble loading up and sending banks of .syx data through Sonar's Sysx View.
Bob Bone