Adding another field to the logon Dialog

Hi Team, 

I'm new to the Telrik Test Studio and was wondering if you can add more fields to the Logon dialog? or is the username and password field standard? 

If so how would you recommend I complete three fields for a logon step? 

I have 1. InstanceName 2. Username 3. Password

If there is any documentation out there or another thread that has the answer that would be GREAT!

Thanks! and sorry if this is a stupid question.