If you use IE exclusively and allow ActiveX calls it is possible to define a Click Action as "Run Script".
That script could (not saying you should) call a JS function named "createFile" with a parameter named "Text", the value for which can be supplied by a Property.
function createFile (Text)
var fso = new ActiveXObject("Scripting.FileSystemOnject");
var s = fso.CreateTextFile("C:\\Temp\\MyTest.txt",true);