Integrating aras innovator with an external database

Hi folks, I have a question and i think you guys can help me. my question is how to change the property of operation number in process plan from Integer to a String. when i tried to change in the properties of mpp_operation which is a item type, it showing error that can't change the system properties. what can i do? because I have operation number something like A0, B0 etc.. and another question is how can i share data from aras database to another external database and vice versa, i mean how can i integrate aras innovator with an external database. Thanks folks..!!