I agree with solaris. I think your goal has to be to take anything in your profile and connect it to the school in a positive way. It doesn't really matter what you have done as long as you can sell it and make it seem relevant.
Why do you want an MBA? You may want to write about how an MBA will allow you to pursue your goal of working in adminstration (executive role, not secretary) at some kind of educational institution by giving you the business training you need to further develop the real world experience you have gained. I'm not saying that's your goal, but it's a relevant example of something that makes sense. Don't ever say, "Well, I did this, but it wasn't that cool, so now I'd like to do this other thing." Say, "I did this, this, and this, and that will help me be better at such and such other thing I want to do. Columbia will help me bridge the gap by providing X training and Y classes."