You can include diacrtical marks in a couple of different ways in most computer programs these days.
First, if you find an instance where the marks are included already, you can just use the copy function to get them into your own writing. That's what I did with ANDRÉ and INÈS; I simply copied them from the entries where they occur on this very site.
You can also use the ALT key in combination with certain number codes in order to create letters with the diacritical marks. I am not sure if this works on all computers, but the codes on the following site usually work for me:http://www.starr.net/is/type/altnum.htm