一个简单的dll调用，该怎么写！ (100分)

这是一个dll里的函数，我该怎样写程序，把其中的12个值传进去 t14为返回值
dll名为eiid.dll
HRESULT _stdcall CreateEIID([in] BSTR t1, [in] BSTR t2, [in] BSTR t3, [in] BSTR t4, [in] BSTR t5, [in] BSTR t6, [in] BSTR t7, [in] BSTR t8, [in] BSTR t9, [in] BSTR t10, [in] BSTR t11, [in] BSTR t12, [out, retval] long * t14 );

我这样写为什么会出错错在哪里了
implementation
function CreateEIID(t1,t2,t3,t4,t5,t6,t7,t8,t9,t10,t11,t12:string):double;stdcall;external 'C:/cs/eiid.dll' ;
{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
pp:double;
begin
pp:=CreateEIID('id','1','2','3','4','5','6','7','8','9','10','11');
showmessage('成功');
end;