Parsing method calls with in a method

I'm trying to build an application that when given an executable path, will return all the data layer methods the application uses. Between the application and data layers there is a business layer that may call other business layer methods, or call one or more data layer methods. I've created a parser that uses the source code, but it doesn't work very well. I see reflection allows you to view types and their methods given an assembly. I would like something of that nature that goes one step further and lists method calls for each the type's methods. Any body ran across this?