Can anyone help?
In your case, the code would be something like:
var sDate = "2013-01-10";
// Convert string to date
var oDate = util.scand("yyyy-mm-dd", sDate);
// Convert date to new string
var sDate2 = util.printd("mm/dd/yyyy", oDate);
// Set a field value
getField("date2").value = sDate2;
The exact code you'd use depends on where you place the script and where you're getting the original date string, but this should get you started.