Many thanks, it's simple when you know the steps.
The use of this command is not intuitive. My first impression was that it was not implemented.
When the command line prompts "Command:" the user is actually expected to click on the Continue Action button (>>) and that's almost impossible to guess.
A better hint is required, maybe pressing the enter key should equal to clicking on Continue Action so the command can proceed to "Specify reference point" and then to "Specify target point".