procedure TExpt.Init( aBeforeText, aAfterText : TMemo; aGrid : TDBGridEh; CreateImmediately, Colored : boolean );
  var b : boolean;
begin
    BeforeText := aBeforeText;
    AfterText := aAfterText;
    Grid := AGrid;

    Excel := CreateOLEObject( 'Excel.Application' );     <---   Здесь выдает ошибку.
    Excel.Application.EnableEvents := false;

procedure TForm1.Button1Click(Sender: TObject);
var exp : TExport;
begin
   exp.Init(bt,at, dg,false, false);
end;

TExport = class
            private
                FExcel : Variant;
            ...
            public
                property Excel : Variant read GetExcel
                                        Write SetExcel;
                procedure Init( aBeforeText, aAfterText : TMemo; aGrid : TDBGridEh; CreateImmediately, Colored : boolean );
            ...
end;

А>procedure TForm1.Button1Click(Sender: TObject);
А>var exp : TExport;
А>begin
A>   exp := TExport.Create;
А>   exp.Init(bt,at, dg,false, false);
А>end;
А>

uses {...} ComObj, ActiveX, Variants;

type
  TXls = class
  private
    fxls : Variant;
  public
    class function IsExcelInstalled(): boolean;
  public
    constructor Create(Visible: Boolean=False; FileName: WideString='');
    destructor Destroy(); override;
  end;

//...

class function TXls.IsExcelInstalled: Boolean;
var
  CID: TCLSID;
begin
  Result:= (CLSIDFromProgID(PWideChar(WideString('Excel.Application')), CID) = S_OK);
end;

constructor TXls.Create(Visible: Boolean=False; FileName: WideString=''; Calculation: TXlsCalculation=xlscNull);
begin
  if(not TXls.IsExcelInstalled)then
    Raise Exception.Create('Excel не установленн!');

  fxls:= CreateOleObject('Excel.Application');
  fxls.Visible := Visible;
end;

destructor TXls.Destroy;
begin
  fxls.Quit;
  fxls:= Unassigned;
  inherited Destroy;
end;