I do have it in my pc, inside a folder tagged as "DVD". IIRC it is from the one of the singles/album specials, which comes with the dvd. I'm putting my guess, Ganbare Otome, Snow Celebration or Daiji na Mono. But I cannot find it in AMP either.... Been a long time already.
Idoling!!! Hajimete no Recording I ~Hyakkaryouran Idoling!!!~
Idoling!!! Hajimete no Recording II ~Ganbare Otome (Warai)
Idoling!!! Hajimete no Recording III ~Kimi ga Suki~
I think it comes together with this :
Idoling!!! - Neoki Dokkiri Video (Snow celebration Bonus Episode)