1. Find the database software that you are most comfortable with (could be Excel indeed, but just as well it's FileMaker or SQL Server Express or MS Access) and start working. With 1 minute per contact it's only 28.000 minutes or some 500 hours if you do it fully manually. So it might be better to do some smart programming.

2. It might help to format the column as text in Excel. Or even the cell by preceding the contents with a quote. But it's far from sure. Details like this show that Excel basically is a number cruncher. You might need a 'real' database program to be able to do it.

3. Sorry, I don't use any of the sites you mention. So I can't tell about that.