>Alejandro, last time I needed to do something like this, I ended up writing code in VB to call the object, and then calling the VB DLL from VFP. I couldn't find any way to explain to the object what kind of array VFP was passing it.

Thank you for your answer. Dicovered the mistake of not properly dimensioning the targets of ACOPY(), but now the problem is that the fucntion doen't change the array. At least I am progressing.