EditorGUI and method create

I'm creating an editor window which will contain a list, ready for string input by the user. Is it possible to create a function in a script based of these string inputs.

For example, imagine a achievement system where you highlight the manager which contains the implementation for the achievements, then you can select Window and then AchievementCreator. I want to be able to input a string, then based off that string, create a custom achievement.

[ newAchievement blahaaAchievement ]

in the main script would create

void newAchievement() { .... }

void blahaaAchievement() { .... }

Is it possible?

Thanks