I wanted to see what other people's ideas were as how to implement this. I have a version working in my game but I feel that it has to many unnecessary steps and since my game will be for mobile I'ld like to keep everything polished. Right now I'm using an array to store all my possible missions, and then another 'Temp'array to store the 3 current active missions. Then at the end of each game I check the Temparray against each possible outcome that could be unlocked. For instance how many coins how many kills, distance traveled. I need to find away to only check the 3 that are in my array but I don't know how to do that since we can't store Variable names in arrays.
I'll try to clarify further if what I wrote doesn't make sense.