Unity constructor injection with other parameter

I have a class with a constructor that looks like the following:

public BatchService(IRepository repository, ILogger logger, string user)

In my DI bootstrapper class, I have the following RegisterType command:

.RegisterType<BatchService>(
    new InjectionConstructor(
        new ResolvedParameter<IRepository>("SomeRepository"), 
        new ResolvedParameter<ILogger>("DatabaseLogger")))

In my client code, I want to instantiate BatchService as follows:

BatchService batchService = DIContainer.Resolve<BatchService>()

As you can see, I have a string parameter called user as part of the constructor to BatchService that is not part of the DI logic. How should I best handle this situation if I need to use user in the BatchService class?