Campaign Scoring

I am looking for some help on this matter "Campaign Scoring".. I am trying to get some Achievements and I thought I'd try to mod the game..so i started at the first check point and modded the game save..and then I put on the campaign scoring plus the 3 skulls.. but when I started the game the scoring was'nt in the bottom right side..so I checked and the skulls were still on but the scoring was off.." it says if continue you will lose your saved game". So what I wanted to know, is there any way you can keep the campaign scoring on when you mod the game?.. as I want to get the Achievements!!