Module CheckCCall {
      mybuf$=string$(chr$(0), 1000)
      a$="Hello There 12345"+Chr$(0)
      Print Len(a$)
      Buffer Clear Mem as Byte*Len(a$)
      \\ copy to Mem the converted a$ (from Utf-16Le to ANSI)
      Return Mem, 0:=str$(a$)

      Declare  MyStrDup Lib C "msvcrt._strdup" { Long Ptr}
      Declare  MyFree Lib C "msvcrt.free" { Long Ptr}
      \\ see & means by reference
      \\ ... means any number of arguments
      Declare  MyPrintStr Lib C "msvcrt.swprintf" { &sBuf$,  sFmt$, long Z }

      \\ Now we use address Mem(0) as pointer (passing by value)
      Long Z=MyStrDup(Mem(0))
      a=MyPrintStr(&myBuf$, "%s", Z)
      Print MyFree(Z), a
      Print LeftPart$(chr$(mybuf$), chr$(0))
}
CheckCCall