I have xml files that contain href file paths to images (e.g. \"....\\images\\image.jpg\"). The hrefs contain relative paths. Now, I need to extract the hrefs to the images
Take a look at Path.Combine
http://msdn.microsoft.com/en-us/library/fyy7a5kt.aspx
You can use Path.Combine with the "base" path, then GetFullPath on the results.
string absPathContainingHrefs = GetAbsolutePath(); // Get the "base" path
string fullPath = Path.Combine(absPathContainingHrefs, @"..\..\images\image.jpg");
fullPath = Path.GetFullPath(fullPath); // Will turn the above into a proper abs path