Using the same (default) backend for customers and agents

[ivit]

We would like to implement that agents could act as customers.

Scenario description:
- some agents (e.g. agent1) belonging to non-IT department could be support for some external projects.
- company IT support staff (IT department) will act also as agents (e.g. agent2)
- for internal support we would like that agent2 could record ticket from the agent1, or in other words agent1 to submit ticket to IT support department i.e. to agent1.

There was an option in old OTRS releases AgentCanBeCustomer which was removed at some point:

In release notes to OTRS 2.4.0 beta1 (2009/04/20):
- (2009/04/15) Removed AgentCanBeCustomer option from agent frontend.

What would be the recommended way to achieve mentioned scenario?
Could we add another DB backend for customers (e.g. "Internal customers") and point to the users table, so the internal users will appear in the list of the customers ?

OTRS 3.0.10
Debian 6.0.1

Thanks,
Igor