What do you mean by random? We could have a huge philosophical discussion about what that means....

Can you order the projects by ID and take the highest value? Or lowest? Or median?

Do you want to use the RAND function?

http://msdn.microsoft.com/en-us/library/ms177610.aspx

Do you need to capture atmospheric noise and process that data in order to select a project?

http://www.random.org/