How do use *.flt graphic filters?

How can the graphic filters of MS-Office (*.flt files) used in own programms?
Is a API documentation or FAQ availible?
For the 16 bit version was an article in the Microsoft System Journal (1992)

Thanks,
Johannes

I just did a bit of digging using dumpbin and I found out that they are
standard DLL files with nearly identical exported functions. Theoretically
one could use LoadLibrary and GetProcAddress to get pointers to the
exported functions. Then the question is, what are the prototypes of
those functions ? I don't know that right now but I'll keep digging.