schedule automatic start for an application

Suppose i want to run a program say vidalia at system startup only on some specific time and day.
eg: 1. From Monday to Friday only when PC is started after 6 pm.
      2. On Saturday and Sunday everytime PC is started.
The following batch file program can do it...

@echo off
IF %date:~0,3% EQU Sat goto yes
IF %date:~0,3% EQU Sun goto yes
IF %TIME% GTR 18:06:26.00 goto yes
IF %TIME% LSS 08:00:00.00 goto yes
:no
exit
:yes
Start /D D:\softwares\Internet\Proxy\"Tor Browser"\ D:\softwares\Internet\Proxy\"Tor Browser"\"Start Tor Browser.exe"
exit