Path to a file in a TestMethod

I have a file in my code (a library) that is required for running the code. In this case it is an XML file. Currently I have it in the root of the main program, and it works fine when running the code. However, I need this file for some information when running unit tests. How should I specify the path so that the file will be found? Currently I use the following code to load the file:

doc.Load(xmlFilePath.AbsolutePath);

For the applicaiton this argument is just

new Uri("QuickDateStrings.xml")

so effectively I have the following:

doc.Load(new Uri("QuickDateStrings.xml"));

Tags: C#, Unit Testing