Do some Excel Work

I need someone to develop a sign-up sheet that can be accessed by multiple users at once. The sign-up sheet may have individuals signing themselves up or one user signing multiple users up. The required fields are Name (First,Last), Department, Building/Floor Location. I have a spreadsheet of the users last, first name, department and would like this to be imported by myself into the program and make it easy for the user to begin typing their information and it pre-populates. I would like the ability to add sessions in which users could sign up and limit the number of spaces available in a session As with the list of users already present, I would like the program to track automatically if a user who matches the same first and last name signed up. (A simple column stating yes/no would work). This would need to be an Office 2010 program and it will be hosted on a network drive. I am on a time crunch and would like it completed in less than a day. Again, I would need to be able to enter the real data in the fields. Attached is a screenshot of a poorly designed spreadsheet that at least meets our field requirements.