>Thanks. I'll probably have to play with this. The actual ZIP4_PARM structure has about 50 fields only one of which is this compound structure so the debugging is going to be fun.

In that case, I'd make an "eleventh" string/object that contains the other 50 fields and concatenate that with the other 10 strings.

>The API was written in C++ and all of the docs are for C++ which I am not versed in at all. I'm really hoping that this struct class of Christof's will work for me here because I think that I would have even a worse time trying to code an FLL in C++ since, apart from the language barrier, I'd still need to have a clearer understanding of how C is working with these structures etc.

As long as you're not dealing with "doubles", you might be OK. I think there's a bug in the convert.FLL when it comes to handling doubles.