library DienstplanRDP_DLL;
uses
  Windows,
  Messages,
  SysUtils,
  Variants,
  Classes,
  Graphics,
  Controls,
  Forms,
  Dialogs,
  ComObj,
  Frm_Info in 'Frm_Info.pas' {Frm_Test};
var
  oXL: Variant;

  {$R *.res}

procedure DLL_Init();stdcall;
begin
  oXL := GetActiveOleObject('Excel.Application');
end;

procedure DLL_Terminate();stdcall;
begin
  oXL := Unassigned;
end;

procedure Test_Excel();stdcall;
var
  Tmp: String;
begin
  Frm_Test := TFrm_Test.Create(nil);
  oXL.ActiveSheet.Cells[2, 1] := 'Test DLL';
  Tmp := oXL.ActiveSheet.Cells[1,1];
  ShowMessage(Tmp);
  Frm_Test.ShowModal;
end;

procedure Test_Frm(Tmp: String);stdcall;
begin
  ShowMessage(Tmp);
end;

exports
  DLL_Init, DLL_Terminate, Test_Excel, Test_Frm;

begin
end.

unit Frm_Info;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;
type
  TFrm_Test = class(TForm)
    Btn_OK: TButton;
    Txt_Box1: TEdit;
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure Btn_OKClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Frm_Test: TFrm_Test;

implementation

{$R *.dfm}

procedure TFrm_Test.Btn_OKClick(Sender: TObject);
begin
// Hier sollte der Aufrauf einer Funktion stehen!?
   Frm_Test.Close;
end;

procedure TFrm_Test.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  Action := caFree;
end;

end.