Database Application

I am very new with Excel and VBA, what i need to do is:
develop an initial log in to open an excel workbook...
and then open the workbook if username and password

1. ask for user name (field should be 50 characters)

2. Ask for a password (password alphanumeric with special characters field 25 characters)

3.Validate user to a salesman data base
if log in attempt fails after 3 attempts, purge buffer, clear log in screen and lock keyboard for 60 seconds)

I have done the whole excel application all i need is this thing to pop up when double click in my direct access to it..

Also save document with the invoice number that in in a cell

and How can I make a cell auto increase the invoice number every time open workbook?