Unlock All Levels
First, open up your Dawn of War\Profiles folder and choose which profile you are going to use. Now go to \W40k\singleplayer\campaign\state1 folder and open up "campaignstate.lua" (make a backup first!) using Notepad or Wordpad. Now you need to find and change the lines with the "maxmission = #" and the "scenario = #". Just change the # signs to whatever mission you want (the maximum is 11 and both # signs have to be the same).