如何用delphi运行一个外部程序，同时指定其安全权限为最小？谢谢！(50分)

如何用delphi运行一个外部程序，同时指定其安全权限为最小？谢谢！
我的思路是：
BOOL CreateProcess
(
LPCTSTR lpApplicationName,
LPTSTR lpCommandLine,
LPSECURITY_ATTRIBUTES lpProcessAttributes。
LPSECURITY_ATTRIBUTES lpThreadAttributes,
BOOL bInheritHandles,
DWORD dwCreationFlags,
LPVOID lpEnvironment,
LPCTSTR lpCurrentDirectory,
LPSTARTUPINFO lpStartupInfo,
LPPROCESS_INFORMATION lpProcessInformation
);
并指定：
LPSECURITY_ATTRIBUTES lpProcessAttributes。
LPSECURITY_ATTRIBUTES lpThreadAttributes,
这两个参数，但不是知道行不行，也不知道如何设置这两个参数，大虾们帮帮小弟。谢谢！

FillChar( lpStartupInfo,sizeof(lpStartupInfo),0);
FillChar(lpProcessInformation,sizeof(lpProcessInformation),0);
lpStartupInfo.cb:=sizeof(lpStartupInfo);
if CreateProcess(nil,PChar(Application.ExeName),nil,nil,false,THREAD_PRIORITY_NORMAL,nil,nil,lpStartupInfo,lpProcessInformation) then
begin
CloseHandle(lpProcessInformation.hThread);
CloseHandle(lpProcessInformation.hProcess);
end;

小弟不才，看不太明白，可否解释一下。

创建一个最小权限用户,或者就用Guest用户权限执行就行了.
const
LOGON_WITH_PROFILE = 1;
LOGON_NETCREDENTIALS_ONLY = 2;
CREATE_DEFAULT_ERROR_MODE = $04000000;

function CreateProcessWithLogon(
lpUsername: PWChar;
lpDomain: PWChar;
lpPassword: PWChar;
dwLogonFlags: DWORD;
lpApplicationName: PWChar;
lpCommandLine: PWChar;
dwCreationFlags: DWORD;
lpEnvironment: Pointer;
lpCurrentDirectory: PWChar;
const lpStartupInfo: TStartupInfo;
var lpProcessInfo: TProcessInformation
): BOOL; stdcall; external 'advapi32.dll' name 'CreateProcessWithLogonW';

wr960204 的方法似乎简单又实用，谢了。不过：
const
LOGON_WITH_PROFILE = 1;
LOGON_NETCREDENTIALS_ONLY = 2;
CREATE_DEFAULT_ERROR_MODE = $04000000;
这几句什么用呀？谢谢！