you can use SQL out of the box without having to write code by using the SQLUM. If you want to get at roles you can use

SourceCode.Workflow.Management Namespace

but to just add destination users you can add them like this

// Add some destination users

            SimpleDestinationRule destinationRule = new SimpleDestinationRule();

            DestinationSet defaultDestinationSet = new DestinationSet();

            Destination destination1 = new Destination();

            destination1.Type = DestinationTypes.User;

            destination1.Value = K2FieldFactory.CreateK2Field("K2:DomainUser1");

            Destination destination2 = new Destination();

            destination2.Type = DestinationTypes.User;

            destination2.Value = K2FieldFactory.CreateK2Field("K2:DomainUser2");

            defaultDestinationSet.Destinations.Add(destination1);

            defaultDestinationSet.Destinations.Add(destination2);

            destinationRule.DestinationSets.Add(defaultDestinationSet);

            // Set the destination rule of the activity

            awaitApprovalActivity.DestinationRule = destinationRule;

Could you help me understand your question better?  Do you want to store users who are not in AD in a database, or do you want to dynamically select users for a destination based on some criteria. 

Also, please confirm that you are using K2 blackpearl. 

K2ROM is actually the K2.net 2003 runtime API.  K2 blackpearl has more options around how to handle Activity Destinations than K2 2003 so it is important to understand what version you are using.

Where would I find the K2FieldFactory?

And I'm a little confused with the activity since the KO activity doesn't have the desination rule property.

 Am I suppose to enter this code in a server code event or in something else?

 As you can tell I'm new to this object model.

Thanks,

Z

well the simple part was actually taken from the Developer reference. but to get at destrules you would use

sourcecode.workflow.authoring

 Zeppelin, were you able to make it work ? Appreciate if you could share the solution.

Thanks in Advance