>I suspect that Rick's anticipated performance gain includes allocation of memory external to VFP's housekeeping so you can process quickly with persistent pointers and minimal re-reading of start positions or error check or other overhead,

Correct. It's the only way to fly.

> then restore the result to VFP variable space if necessary.

Only the functions FTRANSFORM(), FLEFT(), FRIGHT(), FSUBSTR() will return VFP strings.

Faststring.dll will also be suitable as-is for use in C# or other system that can access DLLs. When used as an FLL it will provide tighter integration to VFP.