Int 21 Fn 5F97  - LANtastic - Copy File                                    [N]

   AX = 5F97h
   CX:DX = number of bytes to copy (FFFFFFFFh = entire file)
   SI = source file handle
   DI = destination file handle

Return: CF clear if successful
       DX:AX = number of bytes copied
   CF set on error
       AX = error code

Note:  copy is performed by server