If your talking doing the same thing but through a script it is identical but using script functions. You would need to do a system.tag.read(tag path).value to get your seconds and store it in a variable but then you would insert your variable into the script. Then it depends where the script is to how to put it in the label.
time = system.date.format(system.date.addSeconds(system.date.midnight(system.date.now()),insert your seconds val here),"HH:mm:ss")