library Ddll;

function CalcInOut(A:Integer):Integer;  stdcall;
begin
 Result := A - 123;
end;

procedure TextInOut(var vStr: WideString); stdcall;
begin
 vStr := vStr + ' Ok!';
end;
exports
 CalcInOut name 'DllCalc',
 TextInOut name 'DllText';
begin
end.

Declare PtrSafe Function DllCalc Lib "R:\Win64\Debug\Ddll.dll" (ByVal Val As Integer) As Integer '
Declare PtrSafe Function DllText Lib "R:\Win64\Debug\Ddll.dll" (ByVal Ptr As LongPtr) As LongPtr '
'
Sub Macro1()
  Dim Str As String
  Dim Ptr As LongPtr
  Selection = DllCalc(0) '
  Str = Selection.Text
  Ptr = VarPtr(Str)
  DllText (Ptr)          '
  Selection = Str
End Sub