For the Command Line (and because you are using SMP 2.3) because it works on the ATE, and not the WPF client you would need to wait until the feature is in the WPF Client which is targeted later this year.
I would also recommend you upgrading your ATE, as ATE Version is Agentry v6.1.0.3 is SMP 2.3.0 version and not SP03 (or SP04 which is released)
You can also try the OpenURL action step. See more information on OpenURL Here: SyBooks Online