Deferred Request (WC) Function Call

I'm looking at implementing an Approval Workflow that will go through some actual approval steps but for the final step I want to check that a few things are set to specific values in the database. Looking at the documentation for the Deferred Request Approval Procedure, I think I should be able to do this. My question is around the function that it uses. The example gives dbo.<function name>. So I suppose this is going to be SQL? I would prefer to do it in VB if that's possible. Where do I define this function? Do I need to go into sql and define the function there or is there somewhere within One Identity that I can define a SQL function that I can refer to for this Approval Procedure?