Use IIf statement in query to select the earliest of  3 or more event times

I have at least three Event Types (60, 60070 and 65) associated with a patient leaving the department.  A given pt could have any, or all valued in a single record, discrete date/timefields   I need to create a value called Departure that is the earliest time associated with any these 3 events.  In Excel, this would be a simple Min thing.

There are other times I might need to capture the earliest of 4 events.  

I have no VBA or SQL expertise, but much MS Access query experience, so I need this to be in the form of query criteria or an iif statement.  I have no problem with multiple queries I can put into a macro.  

I am building a data warehouse because we have over extended report writer support and I want to be able to run ad hocqueriesStart Free Trial