Neil Patrick Harris appeared on the original UK show, Ant & Dec's Saturday Night Takeaway (2002), as a guest announcer in preparation for the role of hosting the US show.
Based on the UK show Ant & Dec's Saturday Night Takeaway (2002) with Anthony McPartlin and Declan Donnelly who are the Executive Producers and in the End of Show Show of the first episode.
This is not a "Mini-series", it's just a regular cancelled show.
Nicole Scherzinger guest starred in an episode of How I Met Your Mother, Glitter, which Neil Patrick Harris was a main cast member of.