Open a Word Document and other files

In my program, a user enters a file path and then it is stored in a variable. Later on, I want to user to be able to click a button and it then opens that file path they entered earlier. For example, the user enters C:\Temp\test.doc. That file path is stored. Later they click a button and I want it to open test.doc in Microsoft Word.

Is there some way I can just "execute" the path like you would if you used the windows "run" function (start -> Run) and entered the path name (test.doc would just open). I ask this because it would be nice if the user could also enter C:\Temp\test2.txt and then when they click the button later it would open up this document in notepad.

Thanks

Look up Process.Start

Look up Process.Start
Thanks!