Joshua,
VFP can most certainly pass strings by address to a DLL, the DLL can manipulate them and on return VFP sees the changed string. There are two examples of this over on my website showing how to interface VFP with a DLLs written in VC++.
>Preallocation doesn't help. I still believe that the problem is in the data type difference - VB is passing string variables by reference and getting values back naturally, while VFP is producing DLL exception error. that is, VFP cannot pass to DLL the memory pointer to the string variable.
>
>I wish Mr. Stewart of Microsoft enlightens us on the differences in the concept of the string variable in VB and VFP since he should have a shortcut to the people who have designed those languages.