Find files containing string

Question

Occasionally I need to search through all of our archived EDI's trying to find all instances of a particular item. After EDIs are processed they're categorized in various folders. What I'd like to do is create a process that I can pass a string to and it will produce a list of file names (possibly the path too) where that string exists. I could then loop through those file names to produce a report of all instances of the item I'm researching. What I'm asking is how to create a Find Files and Folders for files named[*.*] and containing text[string] within a C# application? Can anyone help me out here? Thanks, Alex