I'm not actually sure what the hidden code might be in the file, but it appears to be just an image file with a FNT extension.
Ah ok, it's a little more than that, but not that much
I know the structure of the file, it's just a matter of writing a small converter to take the bitmap font, whic is acutally an image, and convert it in the FNT format.
Hoping your linkedin contact may shed some light about the external tools... If we could at least get that damn 3D Converter we would be so blessed! Just that one, I don't care about the other tools :P