There is currently no support for directly verifying the contents of a data source, and hence no way to condition non-coded logical steps on their values. You can view the feature request for this feature in our feedback portal. There, you can follow the status of this feature request, as well as vote on the feature, increasing its priority in our development roadmap.
If you implemented such a condition in a coded step, all steps that logical block called would also need to be in code. However, we generally recommend creating separate tests for each test case. If there are multiple tests for each test case, you can generate a test list that reflects each set of tests for that case. This is a matter of testing philosophy: each test reflects a specific case, rather than a variety of cases that turn on the state of the target application. This can ease maintenance in the scenario where the underlying target application changes. Please let us know if we can advise you further.
the Telerik team