Hi,

i've tried to download the SDK but one has to register and then even wait until Canon activates the useraccount.

Since all the declarations use custom typedefs (or defines)
one can only guess what these types should stand for.

at best post the complete header file.

"How do you know which dll to point them at?"
It depends, it could be that Canon only ships a "lib" file for static linking to their code. In this case you cannot use the SDK at all from VFP.
Otherwise just have a look at all the dlls in the SDK with "Dependency Walker" (depends.exe) and you should be able to identify the correct dll.

Regards
Christian