Just noticed that you want to do this after a new row is added. I assume that the user has to remember to click a sort button or some such after adding a new row?
The coding gets a lot more complex but did you know that:
1. You can add a button called "New row", or similar, which would present the user with a nice form to fill in (complete with validity checks if needed),add the row then sort the sheet.
2. There are "events" in Excel which you can attach code to. One event is worksheet_changed which is called every time a change is made to the worksheet. This code could determine if a new row has been added then go ahead and sort.
Just FYI....
PS. I'm a nice guy ;-), if you fancy any of these approaches, PM me and I'd be happy to code this for you.