Bulid a C# library which extracts strings from files

I need a C# library that can extract strings (i.e. button text, labels, etc.) from .html, .js and .cs files. It must be able to find and replace a given string with an other. These functions are required: 1. public string GetAllStrings(string fileName) Returns all strings in List<string> 2. public void ReplaceString(string textToFind, string textToReplace, string fileName) Finds the given string and replaces. In HTML files: it must find all strings from UI elements (i.e. button, select, label, etc.). In CS/JS files: it must find all strings. This is fixed price bid. Please bid only if you can deliver what is requested, at the given price.