C# proxy class

Question

In a C# 2008 proxy class for a console application, I am thinking that I want to add code to the production application. I obtained some code from a contract shop that I want to work with. I want to be able to update the sql server 2008 database and change some directory path locations.

Am I allowing to do this in a proxy class? If so, are there certain rules I need to follow to be allowed to change the code?

If I am not allowed to change the code, can you tell me what my alternatitves are and how to code for these alternatives?